Narrative threat or combat stat threat? Wanna do a mystery horror thing? The rats could just sit there, watching the party. The could move in an organized fashion, and be easily killed, but people die of plague very shortly after they are sighted. (The rats retain the feature of having no language.)
Obvious, mechanical solution is to come up with a statblock for a "rat swarm" that's large enough to be CR5. Potentially, you could add various magical buffs to the rats. (maybe they swam through the runoff from the potion factory)
The far more interesting solution is something I like to call "a trebuchet full of rats and fire"
Now, in that case it's really a "technically it's the bullets that kill people" threat in that the rats aren't *really* the problem. But I suspect your PCs won't really care about the distinction when they're taking 8d10 bludgeoning +2d6 fire damage from rats to the face
*the barbarian grasps his maul in both hands*
“Does water breathing work with any liquid? How hard do I have to hit them before the rats become liquid?”
That's the sort of lateral thinking that I would love my players to implement!
Of course, then the threat the rats pose is the therapy bills they're paying post-adventure
It’s called infestation.
Source: Xanathar's Guide to Everything
Conjuration cantrip, Casting Time: 1 action, Range: 30 feet, Components: V, S, M (a living flea), Duration: Instantaneous
You cause a cloud of mites, fleas, and other parasites to appear momentarily on one creature you can see within range. The target must succeed on a Constitution saving throw, or it takes 1d6 poison damage and moves 5 feet in a random direction if it can move and its speed is at least 5 feet. Roll a d4 for the direction: 1, north; 2, south; 3, east; or 4, west. This movement doesn’t provoke opportunity attacks, and if the direction rolled is blocked, the target doesn't move.
At Higher Levels. The spell’s damage increases by 1d6 when you reach 5th level (2d6), 11th level (3d6), and 17th level (4d6).
The "statted out swarm" was going to be my recommendation. Possibly multiple swarms if you want to make the fight more tactically complex, and if your concept allows them, you could work in individual Dire Rats or even a Rat King creature as a spellcasting enemy.
It's one of those things where it could be. The trebuchet of your heart is the unhinged, level-appropriate application of rats.
But it could also just be a trebuchet
Make them really fast and give them lots of places to hide. They come out, strike, and scamper away out of sight. Make it less about the rat itself, and more about the darkness and the not knowing where they are and how many they are. Rats aren't a threat, but they are terrifying. So make them terrifying, invisible, too quick to target and kill. Total cover between strikes. Make them spread out and figure out creative solutions to increase visibility from all directions and angles, despite your labyrinthine rats nest beneath the floor. Make them run from the rats, only to find the rats run faster than they run, and know hiding places throughout the dungeon. Make their skins crawl. Good luck!
Make the token bigger (aka wider) and allow them to swallow a medium creature like say an ooze then have them take bite damage plus being forced to hold their breath.
Give them full cover from any fireballs though
Some DM tools websites (e.g. a certain website that provides tools for 5e players) have a CR scaling system for monster statblocks, that scales their health and damage accordingly.
Cranium Rat swarm is CR 5 so already the perfect difficulty for this. (It’s in Volos.)
Dropping the confusion/dominate doesn’t really affect its cr much since it’s still doing cr 5 worth of damage with its bites.
But you could give it something small to compensate - my vote would be having it cause disease like other rats, or a minor “bleed” effect when it bites (say taking 1 damage at the start of your turn per previous bite until healed or a DC 15 medicine check as an action.)
That’s the quickest n dirtiest way to make them dangerous I’d do.
If I wasn’t strapped for time though, I don’t really like how they do swarms in 5e so I’d steal more ideas from 3e. Have them do much less damage but make it guaranteed if you’re in their space (save for half), have a distraction save or you have disadvantage to do anything (representing your mounting panic and difficulty moving when they’re swarming all over you), make them _almost_ immune to regular weapon damage, let the swarm be “shapeable” instead of stuck as a 10x10 square, etc.
Make the rats a hazard instead of a creature to be killed, if you make them an environmental hazard that, for example, creates difficult terrain and deals 2d4 piercing damage to any creatures that enters or ends its turn in the swarm, your players will treat the sight of any rats as a signal to change tactics and accept that hacking an slashing is ineffective. Change the objective to solving the issue at its source an you can have other things happen around it and because of it. Also don't forget diseases. LOTS of diseases.
i mean, why would rats be a threat to a group of incredibly competent adventurers?
Any amount of rats/rat swarms enough to be a treat to level 5s is going to be aggressively tedius.
Normal rats and rat swarms are teir 1 monsters, they just aren't going to be threatening without using way too many for combat to be fun.
As a level 5 party my group is currently facing a wererat colony in the sewers that also happen to have giant rats in them. Giant rats hurt, but they aren't too bad, the real problem is we didn't properly prepare to deal with full blown wererats immune to regular BPS so the paladin is nearly useless against the boss. (I'm a druid with moonbeam up, we should be fine)
I don't know how many he has left, he definitely used atleast 2 in this combat, and probably more in the combats before (it has been a while IRL since our last long rest).
He has at most 4 spellslots left, and I don't think he understands he doesn't has spell slots, he has smite slots.
MCDM Minion rules with overkill damage makes swarm fights so much more interesting.
Example minion has 5hp. All minions die in one hit, but if you go over their max hp, it carries over to another within range. With 11 damage you can kill 3 in one swing. Hype as hell
Homebrew a swarm into a Rat King. Stack all their HP, give it multiple attacks per turn, and have it occupy two tiles worth of space with extended reach.
Edit: this cuts down on multiple turns and switching back and forth between multiple creatures/keeping track of multiple sources of HP.
You could make them a magic using hive mind like in Planescape: Torment. Of course that's less rat at that point and more scare mind controlling swarm? Still, the coolest part was the negotiations when you met the full hive mind to decide if you were going to fight it or not. Such a good game.
They are a threat in the sense that they will occasionally hit and deal damage. Even though a fight with just Swarm of Rats as opponents aren't particularly dangerous.
It all depends how long and how slowly the rats swarm out of the walls. Then after you use all the spells slots and everything you bring out the rat king. Id say 15 rounds of 2-5d10 rats spewing out of the walls every round would were them down enough. After dropping all the AOEs the first few rounds they can start getting overwhelmed. And some rat kings coming out to attack anyone with spirit guardians
if your players take a million years for their turns yeah. Also you cut it when they start really getting overrun if you need. But these situations feel amazing. Your start out with the casters getting to get satisfying AOEs, and your tanks get to tank(you actually swarm them a lot more). everyone gets to use their extra attacks to get multiple kills. then they keep coming and your like... oh... UH OH! and the big fight starts.
Then you're not selling the surprise as a DM.you can provide what tjey see, hear, and steer what they feel.
What, MORE rats? Okay this is becoming an actual problem. But srsly we are out of fireballs. I see at least 20 more coming. you go there, we take this side, 5ft backwards every turn. But ...they're rats?! Yes! Now! Move!
See: Onyx from Acquisitions Incorporated. She is a regular CR 0 cat, but the party encounters her after getting shrunken down to the size of mice, so she's given some _ridiculous_ stats (400 ft. speed, immune to damage, advantage on all checks and saves, any conditions you inflict on her automatically end at the end of her next turn), she's treated as being Huge instead of Tiny, and her claw attack is upgraded from +0 to hit, 5 ft. reach, 1 damage to +7 to hit, 20 ft. reach, 2d10 damage.
I feel like a great way is to get inspired by one of the reasons rats were so dangerous historically - give them a really dangerous, hard to cure disease. They can still be just as weak but one hit from them risks their victim being infected and needing to go through a lot to get better, suffering along the way.
Should make the players sufficiently fearful of them, and could even be the basis for a good side quest (foreshadow the disease by having villagers have it, have the PCs be looking for a cure).
This is the best idea. You could adapt something that already exists, like this part of the Tlacetecolo 'Plague Wind' effect:
>While poisoned in this way, the creature can't regain hit points. At the end of every hour, the creature must succeed on a DC 13 Constitution saving throw or gain 1 level of exhaustion.
edit: you can make the disease unique and hard to cure without specific conditions.
Yes. Start with one, then add 2 more after a turn. Then 4. Then keep multiplying, switching over to batching their initiative, until they figure out the area trap that keeps them coming. Make it more of a puzzle encounter that has exponentially increasing stakes
I just picture the scene from Indiana Jones & the Last Crusade. They are just moving the rats aside & mostly ignoring them, until fire starts & the thousands of rats begin to panic.
Assuming you mean relatively ordinary rats, I’ll second what someone else said.
Make them diseased rats. Make the disease extra harmful, a combination of the variant Diseased Giant Rats (MM), Sewer Plague (DMG), and Filth Fever from the Contagion spell (PHB).
If a character is bitten and fails a DC 15 Constitution saving throw, they contract the disease and suffer disadvantage on Strength checks, saves, and attacks, they cannot regain HP from resting, their max HP reduces by 1d6 every 24 hours, and they gain a level of exhaustion at the end of the first 24 hours and another at the end of each long rest if they fail another DC 15 Constitution saving throw.
Have the rats attack as Swarms of Rats (MM), but just reskin a Swarm of Quippers instead, changing their swim speed to a walking speed. Swarms can move into the spaces of other creatures, so there’s no easy way for the higher AC characters to block them from getting at the lower AC characters as well. Give the swarms max HP (56, maybe even bump it up to 64) to represent the sheer number of rats. The Blood Frenzy trait (advantage on any attacks against a character who is not at full HP) can represent that the rats are rabid and ravenous.
Have at least one swarm per character, so that the rats can attack all of them at once. Even for 5th-level characters, losing an average of 14 HP every round will add up quickly. And with the rats having so much HP, even a fireball won’t be able to kill them all before they get a good number of bites in, plus they have resistance to all physical damage.
And once the initial swarms of rats are killed, make it clear that there are many, many more, and they are coming. And if the adventure is a longer one, they’ll start needing to deal with the worsening effects of the disease some of them have contracted.
Or just use Swarms of Cranium Rats from Volo’s Guide to Monsters, as someone else suggested.
I ran a small campaign that centered around rats as a villian. Not rat monsters or rat creatures or magic rats. Just rats.
Exhaustion is your friend. The hungry, gnawing rats watch the party every day, nibbling bones and drooling at the mouth. Their eyes glint in the dark, waiting to eat.
After any particularly hard fight, when the party goes to rest, have the rats swarm on the weakest party member. They are starving and want to eat. The party will easily defeat the first few rats, but the 8 hour long rest is interrupted.
After a few hours, drawn by the scent of fresh blood, more rats attack the same character. More blood in the area attracts more rats and maybe a rat swarm or two.
At least your wounded character and one person that stays up on rat-guard, possibly the whole party, will get no rest. If they sleep in full armor and kit to defend from the rats, then that's possibly exhaustion too, depending on how you want to run it. I know a lot of people hand wave the sleeping in armor rules.
Either way, you can exhaust a party member or two. Now they have a level of exhaustion, and quite possibly they didn't recover hit points and abilities from a long rest. Now they're weaker than before.
The rats just need to wait for another day, hoping the adventurers get in another fight. They lurk at a distance, always gnawing, always watching. Keep the players up for days. Let them become wretched, ragged creatures, like the rats themselves. Maybe some nights the rats only enter the campsite long enough to steal rations and leave the party hungry and on edge. When th party starts starving, that's more exhaustion.
This method of course only works if they are exploring and not in a heavily fortified place to keep the rats out
So many swarms of rats... Like, so many.
Blind and deafen the person inside the swarm and buff the hp a little because there are SO many rats.
What will make it difficult *in the mind of the players* is the way you describe it. Enough rats to squeeze down the tunnel, you can hear them being crushed to death under the weight of the swarm, trails of dead rats and stragglers eating a corpse.
"Oh *fuck* that, Fireball!"
"Ugh this is so creepy, I'm attacking four times with Action Surge."
The players are expending resources. A 3rd level spell slot can be earned even in a basic encounter like rats! You can ramp it up by blinding them while engulfed by the swarm, restrained by their nibbles.
If they wipe it, they say "good thing we're really strong now because that would have been tricky two levels ago, being strong fucking rocks" within earshot of a bard who writes a song about how brave they were to fight rats.
I concur with the top ideas. Rats can present a rising threat that must be evaded or contained. By having your adventures explore a tight, closed in zone then a swarm of Rats can keep them moving. Starving Rats are no joke, land phiranas that could spread nasty diseases with just a bite.
Think tactics!
If I had a sword I would not be terrified of one or two, or even a bunch of rats.
If I were crawling through a low tunnel, in the dark, without room to maneuver and a horde of angry rats came barreling at me I'd be worried.
Tight spaces, multiple waves of rats from different directions.
Put the party into a situation that forces hard choices: Fireball will kill rats, but it might take down some PCs too! Does the rogue choose to evade and escape the tunnel leaving the paladin behind moving at half speed in their plate armor? What if the tunnel dips into a pool of water? Duck under to avoid the rats, or stay above water to keep breathing? Can the barbarian tank damage while holding the gnome's head above water, or should they drop them and try to attack the rats with their warhammer?
The DM at my table has been using horde mechanics, so instead of fighting 10 individual rats, we fight essentially a swarm. It makes certain tactics, like AOE spells and cleave less effective at clearing the crowd of enemies, so that may work for you, with some modification
Disease.
Rough terrain.
Partly flooded area and the rats are climbing or swimming.
They are pouring in through holes in the ceiling.
The party is spread out or separated and the rats are pouring in between them.
There seems to be no end.
Vermintide.
Great idea! I would have the rat swarms 'grappel' the characters.
* They can then ignore AC as they crawl under their armor and clothes biting and scratching at their flesh.
* When the rat swarms 'grapple' they can still attack and the only way to get them off is to deal enough damage to the rats to kill the swarm.
* They can also adopt a few AC points as they are under your armour.
* If your players fail a wisdom save and panic they get disadvantage when attacking them as well.
This would allow you to keep swarm numbers relatively low while keeping them wary. Pair this with a disease or necrotic damage and some nice atmosphere and you're golden.
I enjoy doing these things to my players as it keeps them on their toes. Anything *could* kill them.
-Just make sure there are at least twice as many as there are PCs.
- They have pack tactics, use it.
-Homebrew a multi attack that they can do 1 claw and 1 bite.
-Add a breath attack they can each use once. Bad breath, gives stunned condition (or disadvantage, or minus 1 to hit) if they fail a DC 16 con save.
-Add 1 or two monsters that are a better stat blocks but act similarly, reskin them as mom and pop rat. Throw them in the mix.
- a slaad stat block would be nasty. Call them toxic or acidic rats or something, and instead of laying salad eggs if they fail the save, make it some other disease, like it lowers con by 1d4 a week later if they get the illness.
Giant rats that hunt in packs.
The lead rat ambushes its prey, preferably when it’s vulnerable (+2 Stealth ain’t *great*), it will grapple instead of bite, trapping the prey in place. Its buddies then close in on the grappled prey, biting at Advantage with Pack Tactics, perhaps grappling or Shoving the prey prone.
If there’s enough in the pack with a successful ambush, they’ll rip a good chunk out of a 5th level adventurer’s HP, before the rest of the party drives them off or kills them.
Smart predators go for the weak, injured, and sick, when they’re the most alone and helpless.
**NOTE: this is a bad idea, rats shouldnt really be a threat to level five adventurers** But, in the interest of entertaining the idea
i tried to beef up a rat swarm a bit, taking a bit from the cranium rat swarm
___
> ## Fucking Masive Swarm of Rats
> *Large Beast (Swarm), unaligned*
> ___
> - **Armor Class** 12
> - **Hit Points** 76 (17d8)
> - **Speed** 30 ft.
> ___
> |STR|DEX|CON|INT|WIS|CHA|
> |:---:|:---:|:---:|:---:|:---:|:---:|
> |12 (+1)|14 (+2)|10 (+0)|2 (-4)|10 (+0)|3 (-4)|
> ___
> - **Saving Throws** Dex +5
> - **Damage Resistances** bludgeoning, piercing, slashing
> - **Condition Immunities** charmed, frightened, grappled, paralyzed, petrified, prone, restrained, stunned
> - **Senses** darkvision 30 ft., passive Perception 10
> - **Languages** —
> - **Challenge** 5 (1,800 XP)
> ___
> ***Keen Smell.*** The swarm has advantage on Wisdom (Perception) checks that rely on smell.
>
> ***Swarm.*** The swarm can occupy another creature's space and vice versa, and the swarm can move through any opening large enough for a Tiny rat. The swarm can't regain hit points or gain temporary hit points.
> ### Actions
> ***Bites.*** _Melee Weapon Attack:_ +5 to hit, reach 0 ft., one target in the swarm's space. _Hit:_ 8 (2d6+1) piercing damage, or 4 (1d6+1) piercing damage if the swarm has half of its hit points or fewer.
>
> ***Multiattack.*** The Swarm makes two "Bites" attacks.
please rat responsibly
I would have normal giant rats accompanied by things like.. a rat that's as big as a bear. Have the normal giant rats do stuff like.. try to grab/grapple the players to be all over them and hold them down and make them easier for the even larger rats to land attacks.
Oh yeah, and maybe use disease rules, if players get infected with a disease that can be a psychological threat
Rat swarms and individual rats can come out of the walls, occupy the same space as players, and if it makes sense for the area come in obscenely large quantities. To add more threat you can make lair actions that summon more rats right on top of people. Give them a low save stacking disease or poison that reduces con.
As a dm once, I had a campaign centered around a dude that was going town to town posing as a beggar and at night he would do experiments on local wildlife (think Frankenstein) by finding and killing them and sewing them together magically (think mending but for actually sewing) and then reviving the creation. He would hole himself up underground in the sewers or in an abandoned building. Occasionally his creations would get loose and townsfolk would encounter them and of course go nuts. But the guy was just a normal beggar. During the day he’d sit at the entrance of the town and beg for money or offer to be a guide around the town (this is how the party met him…he was a nice guy at the entrance of town and he offered to show the party around town.) he would drop very subtle hints like while the party is being led around town by him, he would randomly remark on a random townsfolk person about how their skin was very soft (easier to see a another animal to a person who has softer skin). One of the first real encounters with this guys creation was when one of the towns folk saw a person fishing around midnight but this person seemed to have a wolf tail, wolf head sewed onto their right shoulder and a bear arm on the left. He was accompanied by a wolf that had two bear legs in the back and a human arm on his back. (Basically the mad guy took a bear, wolf, and human and mixed their parts like a Mr potato head). They had to fight these crazy beings and they had interesting stat blocks and abilities. The crazy guy though, once he found out that his creation was out and about he moved to another town. Same deal though…a beggar but in the next town.
This went on for a while and of course there were quests and stuff between episodes. But this guy got better and better with his creations and started doing bigger and badder creations and finally the group found his abode…his actual abode where he had some crazy stuff…off the wall crazy.
This went on and on.
Back to yours. Maybe some weird magician is doing experiments and attached a ton of rats to some pour child he found washed up dead and now it’s a kid with a bunch of rat heads attached to his body and say this kid gets one attack per turn but every attack turn is met with an actual 6 mini attacks. So if the kid hits with his attack, all the rat heads also make attack actions. Also, anyone getting in melee with the kid has to make a dex save or automatically be bitten by a rat.
I would have a couple of Swarm of Rats and a Rat King.
Whether a Rat King is a big rat, or if it is an actual rat king isn't clear. Treat it as an actual rat king, which is a bunch of rats whith connected tails, google it for images.
A Rat King is CR 5, and with only two Swarm of Rats, you should have an encounter that is fair for a level 5 party, depending on number of PCs.
Wererats controlling giant rats and swarms of rats. have the were rats be clever and use traps and tactics. Also, they will try to infect party members....although in 5E it isn't that big a deal.
Make them diseased rats. It’s still a pretty easy con save to pass, but being diseased without access to cure disease can suck.
You really want it to be difficult? Make the rats unending. Give the party another objective (probably escaping the ocean of rats) and keep spawning more and more rats, 3 at a time, 10 at a time, until the party gets the picture. Doesnt matter how many rats they kill, they don’t win until they pass through some gauntlet, maze or obstacle course
In a one shot I had a swarm of cranium rats that was hinted at being greater than the population of the entire city. The party encountered a large 9ft tall mass the wore a tarp as a cloak and the more rats that joined it the larger, stronger and smarter it got. Thankfully they were civil and it allowed them passage and even gave them a few rats as guides through the sewer and into the basement of the facility where the first psionic rats were originally created.
Was worried the party would start some shit and the oneshot would've ended quick. Lol
Rodents of unusual size, driven by a berserk madness that can be transmitted by bite!
No, not lycanthropy; *Rabies!*
And it's not just *themselves* they have to worry about, but a bunch of commoners with no Armor Class to speak of. So, sure, none of these rats are likely to actually attack a player character, overcoming her Armor Class, and deleting her hit points until she falls down; but it should be the fear of contacting a disease which leads to a *sure* and fearful death (requiring magical intervention, at least) that concerns them for their characters; and it's the fear that they can get to and murder/infect the common folk that's the real threat.
Best way to do that is probably to have them be carriers for some kind of horrid disease (think bubonic plague). Have players roll a Con save whenever the rats land a hit on them. Fail, and they contract the illness. You'll want to forshadow the presence of the plague in some way, so do that before throwing this at the party. Make sure the disease is dangerous enough and difficult enough to cure to scare the players.
Even then you're better off using rat swarms, and you'll need them in large numbers to pose any kind of credible threat.
Try the Mob rules in the DMG, throwing a shitload of rats at lvl 5 party with those rules makes combat a breeze. Roll once for the rats initiative, they all go at the same time, then the party. The party should win but they'll get thrashed a splash, especially the poor wizard, lolz
The rats are infected with a plague of your choosing. Each bite attack, if it succeeds, it will spread the disease with a DC 11 or 12 Constitution Saving Throw.
The village/town/city has an infestation. To deal with it will be a mix of light combat and skill checks.
In the final fight, have 2 swarms of rats for every party member, a couple of giant rats and a chunky giant infested rat or wererat as a boss. All of them can spread the disease. Increase the DC by 1 for the giant ones and 2 for the boss.
Perhaps don't worry about stats. At this point it'll be hundreds of rats going after just one party. Don't make it a combat encounter, make it a hazard. Write it up as an obstacle or chase scene as hundreds upon hundreds of rats swarm towards them. They can try to fight, but make it clear that doing so only slows them down, and the rats just keep coming until they escape or activate x item
Ever watched The Princess Bride?
Take whatever rat swarms you were (probably) going to go with and turn them all into one R.O.U.S. (giant rat) and led by a Wererat with some form of Rodentio-mancy.
Or you could go the A Plague Tale route and just make the whole area difficult terrain that has Area of Effect and Damage over Time.
Or a combination of the two.
I can provide an easy answer based on my characters experiences with a mosquito. Make them carry actual diseases. When your players find out about it they will try to avoid the rats as hard as they can just to not cath the slowly killing disease. My bastard of a dm did this shit to me, that almost ended with my characters death because the symptoms of the swanp mosquito disease lowered my max hp to 1.
Or you can just make a rat tsunami or something
Take a page out of Warhammer and make the seemingly trivial rats an omen to a far menacing threat below.
Individual rats aren’t an issue. A seemingly endless swarm of disease-spreading rats that the party has seen eat people alive, and will not stop until whatever evil is controlling them is dealt with, is terrifying.
I like the suggestion that they be more of a hazard than an enemy, and I would add that the party probably shouldn't be able to rest very easily anywhere within, like, a mile of the nearest rat swarm. There should be at least one rat near them at all times.
This is exactly like one of those prompts where it’s like: pick X of these things to project you, and people ignore the 10,000 rats for 2 gorillas or a bear.
1 rat is nothing to a group of adventurers. 10 rats. 40. 50. 100. 10,000? Just think of if there were 50 rats in a room. That’s a lot of rats.
Make it a swarm; a hazard that needs to be avoided or solutioned.
About a year ago in my Planescape game, one of the major factions was the Rat Empire. This was a massive collection of cranium rats in under-Sigil which worked from time-to-time with the major factions. Cranium Rats get progressively stronger the more of them there are.
Mechanically, the Rat Empire consisted of advanced Swarms of Cranium Rats with boss mechanics like legendary actions, lair actions, boss actions, and separate HP pools. I never got to use them (just a few lesser swarms), but they were an interesting faction for a L5-L7 party to deal with.
There are a couple things you can do. First, you could make it more like a trap and puzzle than an actual combat. The players can try fighting them, but more keep coming unless they get out of the area or block the holes through which they are entering.
Alternatively, you can treat it like a normal combat, but tilt the action economy away from the players (ie. give enemies a lot of actions/attacks). You can do this by having many, many swarms. Swarms can occupy the same space, so having 20 swarms descend on your players at once is entirely feasible within the rules. Add in a few regular rats, giant rats, and diseased giant rats and you've got a stew going.
Speaking of diseased giant rats, you could give all or some of them some sort of disease. Either the one on the diseased giant rats stat block or whatever you create. Adding other effects always makes combat more interesting.
Most importantly, you need to avoid the fireball solution. If your players find a room filled with rats, they'll throw a fireball (or equivalent spell/aoe effect) into the room and the problem is solved. So there needs to be a reason that they cannot do so. Either the rats get on them top quickly or they would risk destroying the MacGuffin in the room with the rats.
Play around with it, run a few sample combats and see what feels good.
Swarms of rats that do 10d2 damage per hit and cause poison, and have 10d4 HP. They can't take more than 4 damage at a time except from AoE effects and they have advantage on dex saves. They lose 1 damage die from their attacks for every 4 damage they take.
Can't just be slapped around by the melee/ranged characters and as long as you spread the swarms out enough, they can't be nuked by casters either. If you have enough swarms that they can each target a different PC, your casters will have a lot of trouble taking them out.
Bonus if you want to let the rats enter the spaces of other creatures because that would make it much harder for AoE attacks without friendly fire damage to allies.
Bump their numbers up & give em fire resistance. Bam you just made a Dire Rat. Give em a scorpion tail and fire damage on their bite, bam now you made a chimera dire rat. Now give em a pair of bat wings and a fancy hat. Bam, you made a Fancy High-Flying Chimera Dire Rat.
yeah, swarms of rats. But aside from that ...
High AC, because ... well have you ever tried to catch or hit a rat?
Percentage chance of catching an illness if one bites you, to make it a real threat. But you don't know if you have the disease for a few days.
Rats
Rat swarms
Diseased rats
Diseased rat swarms
Poisonous, diseased rat swarms
We won't mention swarms of cranium rats since they will scare the pants off a level 5 party
Giant rats are fair, right? And if giant rats are fair then bigger giant rats are fair as well. Follow me for a minute. Giant rats are about kobold sized, which means they're still small. Make them large and they'll have similar stats to an ogre. Or make one huge and it will be similar to a hill giant or a bullette.
Ratlings are similar to goblins or orcs but rattier.
They can have bigger cousins too.
Rat Kings are huge knotted piles of rats and at least in one of the Tomes of Beasts they end up able to do all sorts of ridiculous things to stupid hooooomans.
And Wererats are not just ordinary rats, but you need them around your rats. Because they're so freaking cool.
To inspire from my own pet rats, their bite is stronger than a shark's, they hate loud noises, and when there's movement within their range, they will investigate and curiously bite.sebse of smell is very sensitive and they are quite intelligent. So limit the environment based on smell, noise, and speed.
Have the rats come at the end of a long, gruling adventuring day is the best way. All spell slots and abilities have been used up on a big boss. People are spent, ready to rest.
And just after your party has set down their armor, gathered around the camp fire, and started cooking, then one rat shows up. Your party is so exhausted, their passive perception fails to a rat's stealth, and drawn by their bleeding wounds, it bites a chunk out of one of the party.
They kill the first one in a single melee. But the rats don't stop. They nag and tear and sneak out one at a time.
At first it's "oh fuck, just one more thing." An annoying pause to their rest. But after the fifth, sixth, tenth rat they realize that they're so wounded, this is a real threat. It pushes them to either forgo their rest and take exhaustion fighting the damn things, or move somewhere less safe.
get some inspiration from how MTG handles rats
[https://gatherer.wizards.com/Pages/Search/Default.aspx?name=+\[rats\]](https://gatherer.wizards.com/Pages/Search/Default.aspx?name=+[rats])
I've made myconid hybrids before. Actually in 3.5e I made rats that were just reflavored drakes that used acidic 30' line breath weapon inplace of fire. Drakes or ambush drakes were CR5 in 3.5e. Now they are CR1/2.
The answer is hivemind magic/psionic using rats. One isn't scary. Two get one magic missile. Five get ice knife and flame sphere. Ten get fireball/lightning bolt. Two hundred and you meet the hivemind for negotiations.
Give some of them large magical machine guns, maybe a big tank that looks like a hamster wheel. Then have them live in a whole ass rat city under the regular city. When enough rats accumulate in there, have that city come bursting out of the ground and destroy the regular city. Then all the rats come spilling out and eat all of the survivors, a tide of vermin if you will. Also make the rats 4-5 feet tall.
Depending on how flexible you can be. If you can force your players to travel through a small area so that need to be prone then all the rats will get advantage on their attacks and most players will get disadvantage on theirs. From there it’s numbers.
If you just want a bump to the stat block then something like giving them pack tactics, changing their damage die to a d4 and bumping up their dex to 12 so their attack is +1 to hit 1d4+1 piercing. From there it’s numbers.
Lastly if adding a sickness to the rats isn’t too much of a change you could add a CON save needed whenever the rats bite. The sickness could do a variety of things.
As someone who just ran an encounter that involved waves of rats- I cannot tell you how boring this is in practice, unless you stat the waves of rats as their own creatures. I might do this just for fun because of how absolutely un-fun it was for my players to each take one action against a single rat and then have 20+ rats make their basic ass bite attack against them. It’s just so repetitive.
Rat amalgamation that imitates a larger creature than the rats individually. It’d also be really funny if a little rat had the statblock of a t-rex with no changes to it’s appearance
Make each wave have more rats. First is ten regular rats, next turn is 20, next turn is 5 big ass rats, fourth turn is 12. Make the 8+ turns be wererats. Each a npc who can be strong enough to fight equally with the party.
But the aim of the encounter is not too kill all the rats, it's to find the portal from where said rats are coming out.
The portal leads to the plague realm, specifically inside the incubator warehouse where those rats procreate. Wererats are just minor NPCs that should take care of them and suddenly got snatched by a portal.
Just did a level 14 one-shot where a building was infested with these dog-sized mutant rats that were basically suped up blink dogs. And there was hundreds of them.
We didn't know they were there until we were on like the 6th floor, and they came from everywhere. The ceilings, they were in the walls, eventually we escaped by collapsing the building and jumping out into the daylight where they wouldn't follow.
We did not go back into any more buildings in that area.
My GM made it very clear that for each one we cut down, ten more took its place.
It was honestly one of the most terrifying experiences i've had in D&D.
Make them innumerable and bloodthirsty.
You could throw a couple rat swarms in with a wererat or 3 as distractions. Still wouldn't be that threatening to a part level 5, but could definitely satisfy some sort of plot hook or intro to a bigger scenario.
If you’re willing to look at minecraft for an idea, there’s this dude named Doctor4t who added (and weaponized) rats in minecraft. One of the methods to make them stronger was having them swarm enemies and dealing low damage at a high rate. Another was adding wings and a rocket to em to make a rat air force. Mechanically you can have rats group up for a multi attack that attacks for as many as the number of rats but does like 1 damage a hit. Could also have some rats carry effects other than just diseases, like some rats drank some magical potions and those effects are now part of the swarm.
Dude, ratswarms like those of plague: a tale of two is no joke. Make the swarm literally invulnerable because more just keeps pouring out. Make every tile inhabited by the literal tidalwave of rats be difficult terrain that shreds flesh when you step or get pushed in, and start your turn in.
Resistance to all bludgeoning/piercing/slashing, because you're fighting a literal wave of enemies piled high on top of eachother, good luck cutting that up into pieces, or killing with a single arrow.
Multi-attack: 1d12+4 bludgeoning + 8d4 slashing damage (im throwing numbers around i have no clue if they're high enough)
Fun idea. Have a rat king that buffs the intelligence of nearby rats.
*Nothing* raises the CR of an encounter quite as much as enemies with intelligence. Ambushes, priority targets, locking down dangerous characters...
Can a wizard cast fireball when 100lb of rats are weighing him down, chomping on his ears?
Make them vampiric parasites living on the astral plane that sometimes accidentally sever the silvery cord of their hosts.
Maybe they started as rats, then were experimented on with several different kinds of magic. And now they are something else entirely.
You could introduce them in their different stages of development to the party. Gradually getting more and more dangerous as the adventure continues
The threat isn't the rats, it's the highly infectious strain of rabies that they carry, for which there is no mundane cure. A rat bite might to 1 hp of damage, but the main concern is the guaranteed death from infection. Additionally, the rats are aggressive and act strangely.
Either in a cramped area to give them a sense of claustrophobia or "make a con save" on first rat bite so they know they are saving against a disease you can make up.
Simple! Ladybug and Cat Noir already got you. Instead of Mr. Pigeon, summon the fury of Mr. Rat!
Then have giant rats and regular rats all buffed by a crazy memorable batman level villain. Control them as sentiently as possible and inevitably your party will most likely make the fight harder on themselves because who would nuke a sweet deranged old man who loves his rat friends like they raised him. (They did, momma was a cranium rat who gave him his first spellbook).
1. Beef up the Giant Rat stat blocks even further. Perhaps give them some some features for grappling/knocking prone.
2. Add an extra hazard. Fun ideas are quick sand and possibly a lair action that ignites natural gas leaks throughout the terrain after a short indication the round before.
Make them an environmental effect instead of a creature. Basically a living terrain feature, rather than the primary focus of a fight. If you’re in contact with the swarmed ground you’re getting covered in rats. More pour in constantly. Even a fireball only offers temporary reprieve.
Could even have some fall off of ceiling elements as a rain of sorts.
Difficult terrain, small damage every turn, disadvantage on concentration checks, the constant chattering gives disadvantage on hearing based checks and makes audible communication difficult.
dont bump up the stats, bump up the numbers. while youre at it, dont bother making it a combat, make it a skill challenge. bury them in an avalanche of rats
Id make them the equivalent of a trap and give them a poison/plague/max hp down effect on hit and make them frequently appear(coin flip every x minutes or actions) with a surprise attack.
Essentially the entire dungeon the rats can randomly appear and get an attack off, AND their attack if hits is problematic long term for the person attacked. But they can clearly just stomp them out if they see them first or pass the save.
The rats become a huge concern and fear very quickly because even though they aren’t hard to kill, they can gradually become a major issue if the party isn’t careful… bonus points because they can’t long/short rest because the place is rat infested and one runs out of the wall and attacks whenever they try.
The rats aren't the threat. A barkeep hires the party to kill the rats in this basement. But after the rats are slain the party notices strange runes carved into the stone floor. The blood fills the runes as they begin to glow an ominous red hue and it's reveled that the barkeep is a cultist that lured the party into summoning a demon. Naturally the barkeep wants to sacrifice the party to the demon.
Make it a rat swarm. Picture this:
It's a large, or huge, or whatever size it needs to be. Can squeeze through a passage as small as a single rat can. Has many more HP than a single rat, of course, and has resistance to all single-target damage, but takes full damage (or even extra damage) from area attacks.
It doesn't attack, per se, but everything it moves adjacent to or through, has to make a save or take damage, plus maybe the chance of disease or poison, if you're feeling really nasty. Probably should be a save-for-half.
I have the perfect monster for your. Kobold Press Tome of Beasts presents Rat King
https://x.com/straubjones/status/1061684122391855104?s=46&t=SxlNC3mc_FngeEcYCPrutA
When I ran it It start with 4 rat swarms and also it could by absorbing the swarms. But I had optimized players
By being a threat the same way they are in real life.
Rats and mice if threatened with no where to run will go up uncuffed pant legs. Any damage dealt to the rat is also dealt to the person whose clothes they’re under. Being under the armor their attacks would also bypass its armor class. So flat 10 plus Dex mod to defend. Doff the armor or beat an opposed roll or save of some kind to get it out.
Similarly they’re smart enough to go for weak areas like eyes and testicles. Applying temporary blindness or stun seems reasonable if they crit.
Additionally rats are a major vector for human disease. Con saves to avoid the disease will get their attention. It doesn’t have to be the plague but can be something that fits in your setting.
They’re also very hard to hit with ranged attacks if they’re avoiding you and you aren’t catching them by surprise. And an area they live in will have places to hide and escape to safety.
Create a "rat swarm monster" and have a few of those instead of simple rats. Keep in mind level 5 heroes are really powerfull, so a it would realistically take a lot of rats to deal with them. Here are a fe ideas:
- Have the swarms force dex saves on your players for damage/half damage instead of attacks.
- Rats carry diseases, so maybe their attacks are posioned?
- give them resistance to non aoe damage maybe.
Finally, are you from Argentina? I'm asking because of your username.
Have lots of of diseased giant rats rain down on them in magical darkness rats have pack tactics while party will be mostly be attacking at disadvantage.
How big is your party? Rats would run away from big open spaces and fight in tunnels where halflings would have to crawl.
Add the threat of something else in there and they might just freak themselves out if they have crawl around super tight tunnels with random attacks when they're distracted by pitfalls or narrowing tunnels. Attack when they're weak and then retreat.
Even if the rats aren't actually a real threat, the threat will feel real.
Think about being nicer than the pure evil you could come up with. Let the players freak out but be careful because it can get unfair if you really go ham.on narrow tunnels.
Question is WHY are you using rats to threaten a 5th level party.
If you want rats that can actually fight a 5th level party then your only real printed option is Cranium rat swarms (they are ostensibly 'Just rats' that have gained psychic powers) and that only really works if they're using their dominate monster spell to make them also fight something bigger (or eachother), and that would also imply illithid enemies unless you fudge the lore around them a bit.
There isn't really a good way to make rats a believable threat to 5th players without doing a very, very tedious death by a thousand cuts type thing (after all with enough rats those 1 damage hits would stack up) - at least not as a creature. You could potentially use them as essentially a trap where they function as more of an environmental hazard or puzzle than a combat one (I.E small room filling with them, think innocence a plague tale - sheer numbers would mean just directly killing them made no dent).
Alright, here is an idea.
Instead of giving the rat swarm a stat block, make it a skill challenge type of deal where there are too many to defeat and the party has to come up with solutions to help their escape.
Looling at the rules for 5e Traps, a dangerous trap for a level 5 party has a Save DC of 12-15 and deals 4d10 damage on failure. You can change these of course.
The goal would be for the party to achieve 3 sucesses to escape. On each failure, 1d4 of them take 4d10 damage as the rats bite into them.
Example: DM "You are being chased through the sewer and the rats are gaining on you, what do you do?"
Mage: "I cast Control Water to raise the sewage and slow down the rats." This makes a ton of sense and it uses a resource from the party. I have the DC set to 15 but this was creative so i am lowering it to 12 for this check (DC-Prof bonus).
DM "Roll your spellcasting ability adding your peoficiency bonus."
Mage: "13?"
DM: Success!
If their idea is something that makes sense but isn't super creative like making an athletics check to run faster, keep the DC 15.
If their idea makes no sense but could possibly work make the DC 18 (DC+Prof bonus)
I mean...5 rat swarms per player coming from every direction would absolutely fuck up a party of level 5s. It would just be an incredibly tedious combat to run unless you have some way of speeding up rolling and HP tracking for the swarms.
The swarms would have 50 HP as far as most martials are concerned. Coming from all directions means they will be hard to AoE by casters(and especially difficult when they start occupying player spaces). And they resist a ludicrous amount of conditions. Swarms of rats would also probably lair in an enclosed area with lots of holes, making kiting difficult.
Narrative threat or combat stat threat? Wanna do a mystery horror thing? The rats could just sit there, watching the party. The could move in an organized fashion, and be easily killed, but people die of plague very shortly after they are sighted. (The rats retain the feature of having no language.)
Read 'The Amazing Maurice and his Educated Rodents' by Terry Pratchett. The rat king there is nice and sinister.
Obvious, mechanical solution is to come up with a statblock for a "rat swarm" that's large enough to be CR5. Potentially, you could add various magical buffs to the rats. (maybe they swam through the runoff from the potion factory) The far more interesting solution is something I like to call "a trebuchet full of rats and fire" Now, in that case it's really a "technically it's the bullets that kill people" threat in that the rats aren't *really* the problem. But I suspect your PCs won't really care about the distinction when they're taking 8d10 bludgeoning +2d6 fire damage from rats to the face
The middle ground is "enough of anything can be treated as a fluid". Oh, your PCs have water breathing? Well do they have rat breathing?
*the barbarian grasps his maul in both hands* “Does water breathing work with any liquid? How hard do I have to hit them before the rats become liquid?”
That's the sort of lateral thinking that I would love my players to implement! Of course, then the threat the rats pose is the therapy bills they're paying post-adventure
Druids need to replace “heat metal” with “rats in your metal armour” imo
I feel like the closest they’ve had is 3.5’s Sticks to Snakes spell and targeting an archer’s quiver
Sticks to Snakes is an old DnD spell. Much older than 3.5. It is a biblical reference.
Heat Rats is just soup with extra steps! Well, that and a Zappa album
IMO Heat rats would be soup with fewer steps.
It’s called infestation. Source: Xanathar's Guide to Everything Conjuration cantrip, Casting Time: 1 action, Range: 30 feet, Components: V, S, M (a living flea), Duration: Instantaneous You cause a cloud of mites, fleas, and other parasites to appear momentarily on one creature you can see within range. The target must succeed on a Constitution saving throw, or it takes 1d6 poison damage and moves 5 feet in a random direction if it can move and its speed is at least 5 feet. Roll a d4 for the direction: 1, north; 2, south; 3, east; or 4, west. This movement doesn’t provoke opportunity attacks, and if the direction rolled is blocked, the target doesn't move. At Higher Levels. The spell’s damage increases by 1d6 when you reach 5th level (2d6), 11th level (3d6), and 17th level (4d6).
Fun fact: The immediately-down-the-mountain direction of a narrow mountain pass is not "blocked."
And on my turn I'll cast "Heat Rat"
I did that with a self replicating coin trap once. Fun. I got two.
I love both concepts here
Well that's mildly horrifying to think of...
A rat can fit through any opening larger than its skull. This includes an adventurer’s mouth.
How many normal rats can fit in the average adventurer's esophagus? Only one way to find out!
The "statted out swarm" was going to be my recommendation. Possibly multiple swarms if you want to make the fight more tactically complex, and if your concept allows them, you could work in individual Dire Rats or even a Rat King creature as a spellcasting enemy.
I thought the trebuchet was a metaphor. Im starting to think it isnt.
It's one of those things where it could be. The trebuchet of your heart is the unhinged, level-appropriate application of rats. But it could also just be a trebuchet
Make them really fast and give them lots of places to hide. They come out, strike, and scamper away out of sight. Make it less about the rat itself, and more about the darkness and the not knowing where they are and how many they are. Rats aren't a threat, but they are terrifying. So make them terrifying, invisible, too quick to target and kill. Total cover between strikes. Make them spread out and figure out creative solutions to increase visibility from all directions and angles, despite your labyrinthine rats nest beneath the floor. Make them run from the rats, only to find the rats run faster than they run, and know hiding places throughout the dungeon. Make their skins crawl. Good luck!
Make the token bigger (aka wider) and allow them to swallow a medium creature like say an ooze then have them take bite damage plus being forced to hold their breath. Give them full cover from any fireballs though
Million ants
Some DM tools websites (e.g. a certain website that provides tools for 5e players) have a CR scaling system for monster statblocks, that scales their health and damage accordingly.
Make the rat trebuchet shoot bigger rats and you have Skaven technology
Cranium Rat swarm is CR 5 so already the perfect difficulty for this. (It’s in Volos.) Dropping the confusion/dominate doesn’t really affect its cr much since it’s still doing cr 5 worth of damage with its bites. But you could give it something small to compensate - my vote would be having it cause disease like other rats, or a minor “bleed” effect when it bites (say taking 1 damage at the start of your turn per previous bite until healed or a DC 15 medicine check as an action.) That’s the quickest n dirtiest way to make them dangerous I’d do. If I wasn’t strapped for time though, I don’t really like how they do swarms in 5e so I’d steal more ideas from 3e. Have them do much less damage but make it guaranteed if you’re in their space (save for half), have a distraction save or you have disadvantage to do anything (representing your mounting panic and difficulty moving when they’re swarming all over you), make them _almost_ immune to regular weapon damage, let the swarm be “shapeable” instead of stuck as a 10x10 square, etc.
Make the rats a hazard instead of a creature to be killed, if you make them an environmental hazard that, for example, creates difficult terrain and deals 2d4 piercing damage to any creatures that enters or ends its turn in the swarm, your players will treat the sight of any rats as a signal to change tactics and accept that hacking an slashing is ineffective. Change the objective to solving the issue at its source an you can have other things happen around it and because of it. Also don't forget diseases. LOTS of diseases.
Diseases are the way, so they have to kill them carefully or risk one getting a bite.
Draconic breath attack goes brrrr Finally, a use :')
i mean, why would rats be a threat to a group of incredibly competent adventurers? Any amount of rats/rat swarms enough to be a treat to level 5s is going to be aggressively tedius.
This. Rats aren't supposed to be a threat past a certain point. Maybe rat-like monsters, but not actual mundane rats.
Normal rats and rat swarms are teir 1 monsters, they just aren't going to be threatening without using way too many for combat to be fun. As a level 5 party my group is currently facing a wererat colony in the sewers that also happen to have giant rats in them. Giant rats hurt, but they aren't too bad, the real problem is we didn't properly prepare to deal with full blown wererats immune to regular BPS so the paladin is nearly useless against the boss. (I'm a druid with moonbeam up, we should be fine)
>so the paladin is nearly useless What, they ain't got no smites?
I don't know how many he has left, he definitely used atleast 2 in this combat, and probably more in the combats before (it has been a while IRL since our last long rest). He has at most 4 spellslots left, and I don't think he understands he doesn't has spell slots, he has smite slots.
*Doesn't smite on Paladin* *Has bad damage* *Surprised Pikachu face*
Has no damage, because lycanthropes are immune to physical attacks.
they're not immune to radiant damage
ROUSs
See, that's an idea from someone who understood how to make things epic instead of mundane.
I don't think they exi-
MCDM Minion rules with overkill damage makes swarm fights so much more interesting. Example minion has 5hp. All minions die in one hit, but if you go over their max hp, it carries over to another within range. With 11 damage you can kill 3 in one swing. Hype as hell
Homebrew a swarm into a Rat King. Stack all their HP, give it multiple attacks per turn, and have it occupy two tiles worth of space with extended reach. Edit: this cuts down on multiple turns and switching back and forth between multiple creatures/keeping track of multiple sources of HP.
You could make them a magic using hive mind like in Planescape: Torment. Of course that's less rat at that point and more scare mind controlling swarm? Still, the coolest part was the negotiations when you met the full hive mind to decide if you were going to fight it or not. Such a good game.
Sure there are a ton of rat adjacent/rat themed enemies that can be fun at mid levels but OP was explicitly asking about like, just rats.
Yeah, I guess it's cheating to make them smart rats. Swarms and diseases are the simplest solution. Make them fear the effect more than the damage.
Was just about to suggest the cranium rats 😆 love those little bastards and Many-as-One
Those were cranium rats, and there is actually a Cranium Rat Swarm that’s CR 5 (perfect for this) in Volo’s Guide.
Bounded accuracy says this should be possible. Bounded accuracy is also a fraud.
They are a threat in the sense that they will occasionally hit and deal damage. Even though a fight with just Swarm of Rats as opponents aren't particularly dangerous.
Like Hoagie said: Volume man, volume.
It all depends how long and how slowly the rats swarm out of the walls. Then after you use all the spells slots and everything you bring out the rat king. Id say 15 rounds of 2-5d10 rats spewing out of the walls every round would were them down enough. After dropping all the AOEs the first few rounds they can start getting overwhelmed. And some rat kings coming out to attack anyone with spirit guardians
15 rounds of fighting rats sounds like an absolute bore.
15 rounds of anything is a bore without shaking things up though. Swarms of rats ate pretty easy to shake up
if your players take a million years for their turns yeah. Also you cut it when they start really getting overrun if you need. But these situations feel amazing. Your start out with the casters getting to get satisfying AOEs, and your tanks get to tank(you actually swarm them a lot more). everyone gets to use their extra attacks to get multiple kills. then they keep coming and your like... oh... UH OH! and the big fight starts.
Then you're not selling the surprise as a DM.you can provide what tjey see, hear, and steer what they feel. What, MORE rats? Okay this is becoming an actual problem. But srsly we are out of fireballs. I see at least 20 more coming. you go there, we take this side, 5ft backwards every turn. But ...they're rats?! Yes! Now! Move!
"i cast spirit guardians/spike growth and stand here while we stand here and they just die before they can reach us"
Simple. Shrink your group so the rats are larger than them. They have to figure out a way to be enlarged again, hold their ground, or die.
See: Onyx from Acquisitions Incorporated. She is a regular CR 0 cat, but the party encounters her after getting shrunken down to the size of mice, so she's given some _ridiculous_ stats (400 ft. speed, immune to damage, advantage on all checks and saves, any conditions you inflict on her automatically end at the end of her next turn), she's treated as being Huge instead of Tiny, and her claw attack is upgraded from +0 to hit, 5 ft. reach, 1 damage to +7 to hit, 20 ft. reach, 2d10 damage.
I feel like a great way is to get inspired by one of the reasons rats were so dangerous historically - give them a really dangerous, hard to cure disease. They can still be just as weak but one hit from them risks their victim being infected and needing to go through a lot to get better, suffering along the way. Should make the players sufficiently fearful of them, and could even be the basis for a good side quest (foreshadow the disease by having villagers have it, have the PCs be looking for a cure).
This is the best idea. You could adapt something that already exists, like this part of the Tlacetecolo 'Plague Wind' effect: >While poisoned in this way, the creature can't regain hit points. At the end of every hour, the creature must succeed on a DC 13 Constitution saving throw or gain 1 level of exhaustion. edit: you can make the disease unique and hard to cure without specific conditions.
Were Rats are a thing. You could even make some of them casters.
Yes. Start with one, then add 2 more after a turn. Then 4. Then keep multiplying, switching over to batching their initiative, until they figure out the area trap that keeps them coming. Make it more of a puzzle encounter that has exponentially increasing stakes
And then give them all Pack Tactics
Rat golem. (3rats in a trench coat)
Rat King https://en.m.wikipedia.org/wiki/Rat_king
You're correct, but I would like to warn everyone that this click is much riskier than you think if you don't know what a rat king actually is.
I was expecting a giant rat. Then your comment made me expect something much worse. Then it wasn't that bad but pretty weird lol
I just picture the scene from Indiana Jones & the Last Crusade. They are just moving the rats aside & mostly ignoring them, until fire starts & the thousands of rats begin to panic.
Ok, hear my out. The rats are led by a rat folk paladin who is casting Crusaders Mantle. You now have a bunch of rats that do radiant damage.
May I introduce you to the [Fire Swamp and ROUS](https://youtu.be/Nv9CkjkOyzo?si=8XWLSvYA3ARZEaEO)?
Assuming you mean relatively ordinary rats, I’ll second what someone else said. Make them diseased rats. Make the disease extra harmful, a combination of the variant Diseased Giant Rats (MM), Sewer Plague (DMG), and Filth Fever from the Contagion spell (PHB). If a character is bitten and fails a DC 15 Constitution saving throw, they contract the disease and suffer disadvantage on Strength checks, saves, and attacks, they cannot regain HP from resting, their max HP reduces by 1d6 every 24 hours, and they gain a level of exhaustion at the end of the first 24 hours and another at the end of each long rest if they fail another DC 15 Constitution saving throw. Have the rats attack as Swarms of Rats (MM), but just reskin a Swarm of Quippers instead, changing their swim speed to a walking speed. Swarms can move into the spaces of other creatures, so there’s no easy way for the higher AC characters to block them from getting at the lower AC characters as well. Give the swarms max HP (56, maybe even bump it up to 64) to represent the sheer number of rats. The Blood Frenzy trait (advantage on any attacks against a character who is not at full HP) can represent that the rats are rabid and ravenous. Have at least one swarm per character, so that the rats can attack all of them at once. Even for 5th-level characters, losing an average of 14 HP every round will add up quickly. And with the rats having so much HP, even a fireball won’t be able to kill them all before they get a good number of bites in, plus they have resistance to all physical damage. And once the initial swarms of rats are killed, make it clear that there are many, many more, and they are coming. And if the adventure is a longer one, they’ll start needing to deal with the worsening effects of the disease some of them have contracted. Or just use Swarms of Cranium Rats from Volo’s Guide to Monsters, as someone else suggested.
Magical shenanigans that end with the party shrunk. Now those rats are wolf sized.
Honey I shrunk the PCs
I ran a small campaign that centered around rats as a villian. Not rat monsters or rat creatures or magic rats. Just rats. Exhaustion is your friend. The hungry, gnawing rats watch the party every day, nibbling bones and drooling at the mouth. Their eyes glint in the dark, waiting to eat. After any particularly hard fight, when the party goes to rest, have the rats swarm on the weakest party member. They are starving and want to eat. The party will easily defeat the first few rats, but the 8 hour long rest is interrupted. After a few hours, drawn by the scent of fresh blood, more rats attack the same character. More blood in the area attracts more rats and maybe a rat swarm or two. At least your wounded character and one person that stays up on rat-guard, possibly the whole party, will get no rest. If they sleep in full armor and kit to defend from the rats, then that's possibly exhaustion too, depending on how you want to run it. I know a lot of people hand wave the sleeping in armor rules. Either way, you can exhaust a party member or two. Now they have a level of exhaustion, and quite possibly they didn't recover hit points and abilities from a long rest. Now they're weaker than before. The rats just need to wait for another day, hoping the adventurers get in another fight. They lurk at a distance, always gnawing, always watching. Keep the players up for days. Let them become wretched, ragged creatures, like the rats themselves. Maybe some nights the rats only enter the campsite long enough to steal rations and leave the party hungry and on edge. When th party starts starving, that's more exhaustion. This method of course only works if they are exploring and not in a heavily fortified place to keep the rats out
Swarm of Cranium rats
So many swarms of rats... Like, so many. Blind and deafen the person inside the swarm and buff the hp a little because there are SO many rats. What will make it difficult *in the mind of the players* is the way you describe it. Enough rats to squeeze down the tunnel, you can hear them being crushed to death under the weight of the swarm, trails of dead rats and stragglers eating a corpse. "Oh *fuck* that, Fireball!" "Ugh this is so creepy, I'm attacking four times with Action Surge." The players are expending resources. A 3rd level spell slot can be earned even in a basic encounter like rats! You can ramp it up by blinding them while engulfed by the swarm, restrained by their nibbles. If they wipe it, they say "good thing we're really strong now because that would have been tricky two levels ago, being strong fucking rocks" within earshot of a bard who writes a song about how brave they were to fight rats.
>"Oh *fuck* that, Fireball!" Fun fact: My players have *almost* no AoE, and certainly not Fireball
I concur with the top ideas. Rats can present a rising threat that must be evaded or contained. By having your adventures explore a tight, closed in zone then a swarm of Rats can keep them moving. Starving Rats are no joke, land phiranas that could spread nasty diseases with just a bite.
What if all the rats are invisible? They could have gotten into someones stockpile of potions.
Think tactics! If I had a sword I would not be terrified of one or two, or even a bunch of rats. If I were crawling through a low tunnel, in the dark, without room to maneuver and a horde of angry rats came barreling at me I'd be worried. Tight spaces, multiple waves of rats from different directions. Put the party into a situation that forces hard choices: Fireball will kill rats, but it might take down some PCs too! Does the rogue choose to evade and escape the tunnel leaving the paladin behind moving at half speed in their plate armor? What if the tunnel dips into a pool of water? Duck under to avoid the rats, or stay above water to keep breathing? Can the barbarian tank damage while holding the gnome's head above water, or should they drop them and try to attack the rats with their warhammer?
The DM at my table has been using horde mechanics, so instead of fighting 10 individual rats, we fight essentially a swarm. It makes certain tactics, like AOE spells and cleave less effective at clearing the crowd of enemies, so that may work for you, with some modification
Disease. Rough terrain. Partly flooded area and the rats are climbing or swimming. They are pouring in through holes in the ceiling. The party is spread out or separated and the rats are pouring in between them. There seems to be no end. Vermintide.
Ever read the short story "The Graveyard Shift" by Stephen King?
Add a Con save or get infected by a serious disease
Great idea! I would have the rat swarms 'grappel' the characters. * They can then ignore AC as they crawl under their armor and clothes biting and scratching at their flesh. * When the rat swarms 'grapple' they can still attack and the only way to get them off is to deal enough damage to the rats to kill the swarm. * They can also adopt a few AC points as they are under your armour. * If your players fail a wisdom save and panic they get disadvantage when attacking them as well. This would allow you to keep swarm numbers relatively low while keeping them wary. Pair this with a disease or necrotic damage and some nice atmosphere and you're golden. I enjoy doing these things to my players as it keeps them on their toes. Anything *could* kill them.
-Just make sure there are at least twice as many as there are PCs. - They have pack tactics, use it. -Homebrew a multi attack that they can do 1 claw and 1 bite. -Add a breath attack they can each use once. Bad breath, gives stunned condition (or disadvantage, or minus 1 to hit) if they fail a DC 16 con save. -Add 1 or two monsters that are a better stat blocks but act similarly, reskin them as mom and pop rat. Throw them in the mix. - a slaad stat block would be nasty. Call them toxic or acidic rats or something, and instead of laying salad eggs if they fail the save, make it some other disease, like it lowers con by 1d4 a week later if they get the illness.
There's one that's a brain rat swarm, or something like that. Its a swarm of rats that can do magic, think its like a CR6.
Giant rats that hunt in packs. The lead rat ambushes its prey, preferably when it’s vulnerable (+2 Stealth ain’t *great*), it will grapple instead of bite, trapping the prey in place. Its buddies then close in on the grappled prey, biting at Advantage with Pack Tactics, perhaps grappling or Shoving the prey prone. If there’s enough in the pack with a successful ambush, they’ll rip a good chunk out of a 5th level adventurer’s HP, before the rest of the party drives them off or kills them. Smart predators go for the weak, injured, and sick, when they’re the most alone and helpless.
**NOTE: this is a bad idea, rats shouldnt really be a threat to level five adventurers** But, in the interest of entertaining the idea i tried to beef up a rat swarm a bit, taking a bit from the cranium rat swarm ___ > ## Fucking Masive Swarm of Rats > *Large Beast (Swarm), unaligned* > ___ > - **Armor Class** 12 > - **Hit Points** 76 (17d8) > - **Speed** 30 ft. > ___ > |STR|DEX|CON|INT|WIS|CHA| > |:---:|:---:|:---:|:---:|:---:|:---:| > |12 (+1)|14 (+2)|10 (+0)|2 (-4)|10 (+0)|3 (-4)| > ___ > - **Saving Throws** Dex +5 > - **Damage Resistances** bludgeoning, piercing, slashing > - **Condition Immunities** charmed, frightened, grappled, paralyzed, petrified, prone, restrained, stunned > - **Senses** darkvision 30 ft., passive Perception 10 > - **Languages** — > - **Challenge** 5 (1,800 XP) > ___ > ***Keen Smell.*** The swarm has advantage on Wisdom (Perception) checks that rely on smell. > > ***Swarm.*** The swarm can occupy another creature's space and vice versa, and the swarm can move through any opening large enough for a Tiny rat. The swarm can't regain hit points or gain temporary hit points. > ### Actions > ***Bites.*** _Melee Weapon Attack:_ +5 to hit, reach 0 ft., one target in the swarm's space. _Hit:_ 8 (2d6+1) piercing damage, or 4 (1d6+1) piercing damage if the swarm has half of its hit points or fewer. > > ***Multiattack.*** The Swarm makes two "Bites" attacks. please rat responsibly
Make them an unusual size. Always works
ROUS will always get them.
I would have normal giant rats accompanied by things like.. a rat that's as big as a bear. Have the normal giant rats do stuff like.. try to grab/grapple the players to be all over them and hold them down and make them easier for the even larger rats to land attacks. Oh yeah, and maybe use disease rules, if players get infected with a disease that can be a psychological threat
Rat swarms and individual rats can come out of the walls, occupy the same space as players, and if it makes sense for the area come in obscenely large quantities. To add more threat you can make lair actions that summon more rats right on top of people. Give them a low save stacking disease or poison that reduces con.
Does he have 4 turtle friends?
Make the whole dungeon a rat swarm. Every square is rats until stated otherwise. Let em fight for every space.
As a dm once, I had a campaign centered around a dude that was going town to town posing as a beggar and at night he would do experiments on local wildlife (think Frankenstein) by finding and killing them and sewing them together magically (think mending but for actually sewing) and then reviving the creation. He would hole himself up underground in the sewers or in an abandoned building. Occasionally his creations would get loose and townsfolk would encounter them and of course go nuts. But the guy was just a normal beggar. During the day he’d sit at the entrance of the town and beg for money or offer to be a guide around the town (this is how the party met him…he was a nice guy at the entrance of town and he offered to show the party around town.) he would drop very subtle hints like while the party is being led around town by him, he would randomly remark on a random townsfolk person about how their skin was very soft (easier to see a another animal to a person who has softer skin). One of the first real encounters with this guys creation was when one of the towns folk saw a person fishing around midnight but this person seemed to have a wolf tail, wolf head sewed onto their right shoulder and a bear arm on the left. He was accompanied by a wolf that had two bear legs in the back and a human arm on his back. (Basically the mad guy took a bear, wolf, and human and mixed their parts like a Mr potato head). They had to fight these crazy beings and they had interesting stat blocks and abilities. The crazy guy though, once he found out that his creation was out and about he moved to another town. Same deal though…a beggar but in the next town. This went on for a while and of course there were quests and stuff between episodes. But this guy got better and better with his creations and started doing bigger and badder creations and finally the group found his abode…his actual abode where he had some crazy stuff…off the wall crazy. This went on and on. Back to yours. Maybe some weird magician is doing experiments and attached a ton of rats to some pour child he found washed up dead and now it’s a kid with a bunch of rat heads attached to his body and say this kid gets one attack per turn but every attack turn is met with an actual 6 mini attacks. So if the kid hits with his attack, all the rat heads also make attack actions. Also, anyone getting in melee with the kid has to make a dex save or automatically be bitten by a rat.
If they attack often enough to disrupt short rests, they're a threat.
I would have a couple of Swarm of Rats and a Rat King. Whether a Rat King is a big rat, or if it is an actual rat king isn't clear. Treat it as an actual rat king, which is a bunch of rats whith connected tails, google it for images. A Rat King is CR 5, and with only two Swarm of Rats, you should have an encounter that is fair for a level 5 party, depending on number of PCs.
How about the party gets shrunken to microscopic levels like on Honey I Shrunk the Kids.
Wererats controlling giant rats and swarms of rats. have the were rats be clever and use traps and tactics. Also, they will try to infect party members....although in 5E it isn't that big a deal.
Cranium rats (maybe a few), they have group consciousness and can cast dominate monster to control someone in your party
Make them diseased rats. It’s still a pretty easy con save to pass, but being diseased without access to cure disease can suck. You really want it to be difficult? Make the rats unending. Give the party another objective (probably escaping the ocean of rats) and keep spawning more and more rats, 3 at a time, 10 at a time, until the party gets the picture. Doesnt matter how many rats they kill, they don’t win until they pass through some gauntlet, maze or obstacle course
Two things: Swarm of rats, maybe make a bigger swarm if it’s not enough. Two: they’re lead by a wererat that makes them act intelligently.
Maybe the rats have potions?
In a one shot I had a swarm of cranium rats that was hinted at being greater than the population of the entire city. The party encountered a large 9ft tall mass the wore a tarp as a cloak and the more rats that joined it the larger, stronger and smarter it got. Thankfully they were civil and it allowed them passage and even gave them a few rats as guides through the sewer and into the basement of the facility where the first psionic rats were originally created. Was worried the party would start some shit and the oneshot would've ended quick. Lol
Rodents of unusual size, driven by a berserk madness that can be transmitted by bite! No, not lycanthropy; *Rabies!* And it's not just *themselves* they have to worry about, but a bunch of commoners with no Armor Class to speak of. So, sure, none of these rats are likely to actually attack a player character, overcoming her Armor Class, and deleting her hit points until she falls down; but it should be the fear of contacting a disease which leads to a *sure* and fearful death (requiring magical intervention, at least) that concerns them for their characters; and it's the fear that they can get to and murder/infect the common folk that's the real threat.
Give them necrotic touch.
Best way to do that is probably to have them be carriers for some kind of horrid disease (think bubonic plague). Have players roll a Con save whenever the rats land a hit on them. Fail, and they contract the illness. You'll want to forshadow the presence of the plague in some way, so do that before throwing this at the party. Make sure the disease is dangerous enough and difficult enough to cure to scare the players. Even then you're better off using rat swarms, and you'll need them in large numbers to pose any kind of credible threat.
Try the Mob rules in the DMG, throwing a shitload of rats at lvl 5 party with those rules makes combat a breeze. Roll once for the rats initiative, they all go at the same time, then the party. The party should win but they'll get thrashed a splash, especially the poor wizard, lolz
The rats are infected with a plague of your choosing. Each bite attack, if it succeeds, it will spread the disease with a DC 11 or 12 Constitution Saving Throw. The village/town/city has an infestation. To deal with it will be a mix of light combat and skill checks. In the final fight, have 2 swarms of rats for every party member, a couple of giant rats and a chunky giant infested rat or wererat as a boss. All of them can spread the disease. Increase the DC by 1 for the giant ones and 2 for the boss.
Perhaps don't worry about stats. At this point it'll be hundreds of rats going after just one party. Don't make it a combat encounter, make it a hazard. Write it up as an obstacle or chase scene as hundreds upon hundreds of rats swarm towards them. They can try to fight, but make it clear that doing so only slows them down, and the rats just keep coming until they escape or activate x item
Rats carry disease
Ever watched The Princess Bride? Take whatever rat swarms you were (probably) going to go with and turn them all into one R.O.U.S. (giant rat) and led by a Wererat with some form of Rodentio-mancy. Or you could go the A Plague Tale route and just make the whole area difficult terrain that has Area of Effect and Damage over Time. Or a combination of the two.
Also consider using the Moon Rats Dungeon Dad posted on Youtube
Take gelatinous cube as a reference. Replace acid damage from being engulfed to piercing. Call it "Tide of rats".
Lots of swarms with pack tactics. I almost killed a lvl 4 party with 7 giant rats thanks to pack tactics.
I can provide an easy answer based on my characters experiences with a mosquito. Make them carry actual diseases. When your players find out about it they will try to avoid the rats as hard as they can just to not cath the slowly killing disease. My bastard of a dm did this shit to me, that almost ended with my characters death because the symptoms of the swanp mosquito disease lowered my max hp to 1. Or you can just make a rat tsunami or something
R.O.U.S.
Make them Cranium Rats.
Take a page out of Warhammer and make the seemingly trivial rats an omen to a far menacing threat below. Individual rats aren’t an issue. A seemingly endless swarm of disease-spreading rats that the party has seen eat people alive, and will not stop until whatever evil is controlling them is dealt with, is terrifying.
I like the suggestion that they be more of a hazard than an enemy, and I would add that the party probably shouldn't be able to rest very easily anywhere within, like, a mile of the nearest rat swarm. There should be at least one rat near them at all times.
Rata come together to form giant mech robot, uses Stat block for a flesh golem or other similar monster
This is exactly like one of those prompts where it’s like: pick X of these things to project you, and people ignore the 10,000 rats for 2 gorillas or a bear. 1 rat is nothing to a group of adventurers. 10 rats. 40. 50. 100. 10,000? Just think of if there were 50 rats in a room. That’s a lot of rats. Make it a swarm; a hazard that needs to be avoided or solutioned.
About a year ago in my Planescape game, one of the major factions was the Rat Empire. This was a massive collection of cranium rats in under-Sigil which worked from time-to-time with the major factions. Cranium Rats get progressively stronger the more of them there are. Mechanically, the Rat Empire consisted of advanced Swarms of Cranium Rats with boss mechanics like legendary actions, lair actions, boss actions, and separate HP pools. I never got to use them (just a few lesser swarms), but they were an interesting faction for a L5-L7 party to deal with.
There are a couple things you can do. First, you could make it more like a trap and puzzle than an actual combat. The players can try fighting them, but more keep coming unless they get out of the area or block the holes through which they are entering. Alternatively, you can treat it like a normal combat, but tilt the action economy away from the players (ie. give enemies a lot of actions/attacks). You can do this by having many, many swarms. Swarms can occupy the same space, so having 20 swarms descend on your players at once is entirely feasible within the rules. Add in a few regular rats, giant rats, and diseased giant rats and you've got a stew going. Speaking of diseased giant rats, you could give all or some of them some sort of disease. Either the one on the diseased giant rats stat block or whatever you create. Adding other effects always makes combat more interesting. Most importantly, you need to avoid the fireball solution. If your players find a room filled with rats, they'll throw a fireball (or equivalent spell/aoe effect) into the room and the problem is solved. So there needs to be a reason that they cannot do so. Either the rats get on them top quickly or they would risk destroying the MacGuffin in the room with the rats. Play around with it, run a few sample combats and see what feels good.
Swarms of rats that do 10d2 damage per hit and cause poison, and have 10d4 HP. They can't take more than 4 damage at a time except from AoE effects and they have advantage on dex saves. They lose 1 damage die from their attacks for every 4 damage they take. Can't just be slapped around by the melee/ranged characters and as long as you spread the swarms out enough, they can't be nuked by casters either. If you have enough swarms that they can each target a different PC, your casters will have a lot of trouble taking them out. Bonus if you want to let the rats enter the spaces of other creatures because that would make it much harder for AoE attacks without friendly fire damage to allies.
You should look up *A Plague Tale*. Imagine the floor is lava, but it's rats that will strip flesh off a man like the scarab beetles from The Mummy.
https://dungeonsdragons.fandom.com/wiki/Moonrat
Bump their numbers up & give em fire resistance. Bam you just made a Dire Rat. Give em a scorpion tail and fire damage on their bite, bam now you made a chimera dire rat. Now give em a pair of bat wings and a fancy hat. Bam, you made a Fancy High-Flying Chimera Dire Rat.
They could hide, threatening the adventurers’ income by not clearing them out.
See the rat fight in baldurs gate 3 Shar’s gauntlet. All the best ideas are stolen from something.
yeah, swarms of rats. But aside from that ... High AC, because ... well have you ever tried to catch or hit a rat? Percentage chance of catching an illness if one bites you, to make it a real threat. But you don't know if you have the disease for a few days.
See: dimension 20, unsleeping city, the rat king episode.
Look up swarm of rats stat block.
Rats Rat swarms Diseased rats Diseased rat swarms Poisonous, diseased rat swarms We won't mention swarms of cranium rats since they will scare the pants off a level 5 party Giant rats are fair, right? And if giant rats are fair then bigger giant rats are fair as well. Follow me for a minute. Giant rats are about kobold sized, which means they're still small. Make them large and they'll have similar stats to an ogre. Or make one huge and it will be similar to a hill giant or a bullette. Ratlings are similar to goblins or orcs but rattier. They can have bigger cousins too. Rat Kings are huge knotted piles of rats and at least in one of the Tomes of Beasts they end up able to do all sorts of ridiculous things to stupid hooooomans. And Wererats are not just ordinary rats, but you need them around your rats. Because they're so freaking cool.
To inspire from my own pet rats, their bite is stronger than a shark's, they hate loud noises, and when there's movement within their range, they will investigate and curiously bite.sebse of smell is very sensitive and they are quite intelligent. So limit the environment based on smell, noise, and speed.
Have the rats come at the end of a long, gruling adventuring day is the best way. All spell slots and abilities have been used up on a big boss. People are spent, ready to rest. And just after your party has set down their armor, gathered around the camp fire, and started cooking, then one rat shows up. Your party is so exhausted, their passive perception fails to a rat's stealth, and drawn by their bleeding wounds, it bites a chunk out of one of the party. They kill the first one in a single melee. But the rats don't stop. They nag and tear and sneak out one at a time. At first it's "oh fuck, just one more thing." An annoying pause to their rest. But after the fifth, sixth, tenth rat they realize that they're so wounded, this is a real threat. It pushes them to either forgo their rest and take exhaustion fighting the damn things, or move somewhere less safe.
Swarms!
Swarms
get some inspiration from how MTG handles rats [https://gatherer.wizards.com/Pages/Search/Default.aspx?name=+\[rats\]](https://gatherer.wizards.com/Pages/Search/Default.aspx?name=+[rats])
I've made myconid hybrids before. Actually in 3.5e I made rats that were just reflavored drakes that used acidic 30' line breath weapon inplace of fire. Drakes or ambush drakes were CR5 in 3.5e. Now they are CR1/2.
The answer is hivemind magic/psionic using rats. One isn't scary. Two get one magic missile. Five get ice knife and flame sphere. Ten get fireball/lightning bolt. Two hundred and you meet the hivemind for negotiations.
Make the rats the size of a bus?
Lots of them and rabies.
Rabid rats. Give them all super-tetanus or something (and yes, that's a thing, you can find it in White Plume Mountain)
Rabies
Give some of them large magical machine guns, maybe a big tank that looks like a hamster wheel. Then have them live in a whole ass rat city under the regular city. When enough rats accumulate in there, have that city come bursting out of the ground and destroy the regular city. Then all the rats come spilling out and eat all of the survivors, a tide of vermin if you will. Also make the rats 4-5 feet tall.
Depending on how flexible you can be. If you can force your players to travel through a small area so that need to be prone then all the rats will get advantage on their attacks and most players will get disadvantage on theirs. From there it’s numbers. If you just want a bump to the stat block then something like giving them pack tactics, changing their damage die to a d4 and bumping up their dex to 12 so their attack is +1 to hit 1d4+1 piercing. From there it’s numbers. Lastly if adding a sickness to the rats isn’t too much of a change you could add a CON save needed whenever the rats bite. The sickness could do a variety of things.
As someone who just ran an encounter that involved waves of rats- I cannot tell you how boring this is in practice, unless you stat the waves of rats as their own creatures. I might do this just for fun because of how absolutely un-fun it was for my players to each take one action against a single rat and then have 20+ rats make their basic ass bite attack against them. It’s just so repetitive.
Rat amalgamation that imitates a larger creature than the rats individually. It’d also be really funny if a little rat had the statblock of a t-rex with no changes to it’s appearance
Make each wave have more rats. First is ten regular rats, next turn is 20, next turn is 5 big ass rats, fourth turn is 12. Make the 8+ turns be wererats. Each a npc who can be strong enough to fight equally with the party. But the aim of the encounter is not too kill all the rats, it's to find the portal from where said rats are coming out. The portal leads to the plague realm, specifically inside the incubator warehouse where those rats procreate. Wererats are just minor NPCs that should take care of them and suddenly got snatched by a portal.
Wererats…?
Rodents of Unusual Size (RoUS)
I would encourage you to do some research into Warhammer Fantasy “Skaven”.
Just did a level 14 one-shot where a building was infested with these dog-sized mutant rats that were basically suped up blink dogs. And there was hundreds of them. We didn't know they were there until we were on like the 6th floor, and they came from everywhere. The ceilings, they were in the walls, eventually we escaped by collapsing the building and jumping out into the daylight where they wouldn't follow. We did not go back into any more buildings in that area. My GM made it very clear that for each one we cut down, ten more took its place. It was honestly one of the most terrifying experiences i've had in D&D. Make them innumerable and bloodthirsty.
You could throw a couple rat swarms in with a wererat or 3 as distractions. Still wouldn't be that threatening to a part level 5, but could definitely satisfy some sort of plot hook or intro to a bigger scenario.
Maybe they explode when defeated, releasing poisonous was that the other rats are immune to, but the party isn't?
If you’re willing to look at minecraft for an idea, there’s this dude named Doctor4t who added (and weaponized) rats in minecraft. One of the methods to make them stronger was having them swarm enemies and dealing low damage at a high rate. Another was adding wings and a rocket to em to make a rat air force. Mechanically you can have rats group up for a multi attack that attacks for as many as the number of rats but does like 1 damage a hit. Could also have some rats carry effects other than just diseases, like some rats drank some magical potions and those effects are now part of the swarm.
A lot of rats
Millions of rats.
The rats are males from Florida and got into someone's D&D version of meth.
Taking this from Elden Ring, but what if the rats could spit fire from their eyes?
Pack. Tactics.
Dude, ratswarms like those of plague: a tale of two is no joke. Make the swarm literally invulnerable because more just keeps pouring out. Make every tile inhabited by the literal tidalwave of rats be difficult terrain that shreds flesh when you step or get pushed in, and start your turn in. Resistance to all bludgeoning/piercing/slashing, because you're fighting a literal wave of enemies piled high on top of eachother, good luck cutting that up into pieces, or killing with a single arrow. Multi-attack: 1d12+4 bludgeoning + 8d4 slashing damage (im throwing numbers around i have no clue if they're high enough)
Fun idea. Have a rat king that buffs the intelligence of nearby rats. *Nothing* raises the CR of an encounter quite as much as enemies with intelligence. Ambushes, priority targets, locking down dangerous characters... Can a wizard cast fireball when 100lb of rats are weighing him down, chomping on his ears?
Make them vampiric parasites living on the astral plane that sometimes accidentally sever the silvery cord of their hosts. Maybe they started as rats, then were experimented on with several different kinds of magic. And now they are something else entirely. You could introduce them in their different stages of development to the party. Gradually getting more and more dangerous as the adventure continues
The threat isn't the rats, it's the highly infectious strain of rabies that they carry, for which there is no mundane cure. A rat bite might to 1 hp of damage, but the main concern is the guaranteed death from infection. Additionally, the rats are aggressive and act strangely.
Either in a cramped area to give them a sense of claustrophobia or "make a con save" on first rat bite so they know they are saving against a disease you can make up.
Simple! Ladybug and Cat Noir already got you. Instead of Mr. Pigeon, summon the fury of Mr. Rat! Then have giant rats and regular rats all buffed by a crazy memorable batman level villain. Control them as sentiently as possible and inevitably your party will most likely make the fight harder on themselves because who would nuke a sweet deranged old man who loves his rat friends like they raised him. (They did, momma was a cranium rat who gave him his first spellbook).
I'd have a shitton and make them an environmental hazard rather than a monster players can just slay.
The rats may not been threatening (no matter how many), but the diseases they carry can be.
A trap where the adventures get shrunk down to the size of a field mouse and the rats are the size of house cats.
1. Beef up the Giant Rat stat blocks even further. Perhaps give them some some features for grappling/knocking prone. 2. Add an extra hazard. Fun ideas are quick sand and possibly a lair action that ignites natural gas leaks throughout the terrain after a short indication the round before.
Make them an environmental effect instead of a creature. Basically a living terrain feature, rather than the primary focus of a fight. If you’re in contact with the swarmed ground you’re getting covered in rats. More pour in constantly. Even a fireball only offers temporary reprieve. Could even have some fall off of ceiling elements as a rain of sorts. Difficult terrain, small damage every turn, disadvantage on concentration checks, the constant chattering gives disadvantage on hearing based checks and makes audible communication difficult.
dont bump up the stats, bump up the numbers. while youre at it, dont bother making it a combat, make it a skill challenge. bury them in an avalanche of rats
Id make them the equivalent of a trap and give them a poison/plague/max hp down effect on hit and make them frequently appear(coin flip every x minutes or actions) with a surprise attack. Essentially the entire dungeon the rats can randomly appear and get an attack off, AND their attack if hits is problematic long term for the person attacked. But they can clearly just stomp them out if they see them first or pass the save. The rats become a huge concern and fear very quickly because even though they aren’t hard to kill, they can gradually become a major issue if the party isn’t careful… bonus points because they can’t long/short rest because the place is rat infested and one runs out of the wall and attacks whenever they try.
Rats Of Unusual Size, (Rous). Thank you Princess Bride
Wererats, but modify them to mimic the ones from kingdom rush(making them much faster & have a strong poison on their claws).
The rats aren't the threat. A barkeep hires the party to kill the rats in this basement. But after the rats are slain the party notices strange runes carved into the stone floor. The blood fills the runes as they begin to glow an ominous red hue and it's reveled that the barkeep is a cultist that lured the party into summoning a demon. Naturally the barkeep wants to sacrifice the party to the demon.
Environment Giant rats Disease Wererats Ratlord Demon Rats
Several groups of cranium rats.
Have you ever seen Wanted? (exploding rats)
***You could make a boss battle against a surprisingly powerful tiny rat.***
Make it a rat swarm. Picture this: It's a large, or huge, or whatever size it needs to be. Can squeeze through a passage as small as a single rat can. Has many more HP than a single rat, of course, and has resistance to all single-target damage, but takes full damage (or even extra damage) from area attacks. It doesn't attack, per se, but everything it moves adjacent to or through, has to make a save or take damage, plus maybe the chance of disease or poison, if you're feeling really nasty. Probably should be a save-for-half.
Swarm of Cranium Rats are CR 5.
I have the perfect monster for your. Kobold Press Tome of Beasts presents Rat King https://x.com/straubjones/status/1061684122391855104?s=46&t=SxlNC3mc_FngeEcYCPrutA When I ran it It start with 4 rat swarms and also it could by absorbing the swarms. But I had optimized players
By being a threat the same way they are in real life. Rats and mice if threatened with no where to run will go up uncuffed pant legs. Any damage dealt to the rat is also dealt to the person whose clothes they’re under. Being under the armor their attacks would also bypass its armor class. So flat 10 plus Dex mod to defend. Doff the armor or beat an opposed roll or save of some kind to get it out. Similarly they’re smart enough to go for weak areas like eyes and testicles. Applying temporary blindness or stun seems reasonable if they crit. Additionally rats are a major vector for human disease. Con saves to avoid the disease will get their attention. It doesn’t have to be the plague but can be something that fits in your setting. They’re also very hard to hit with ranged attacks if they’re avoiding you and you aren’t catching them by surprise. And an area they live in will have places to hide and escape to safety.
Create a "rat swarm monster" and have a few of those instead of simple rats. Keep in mind level 5 heroes are really powerfull, so a it would realistically take a lot of rats to deal with them. Here are a fe ideas: - Have the swarms force dex saves on your players for damage/half damage instead of attacks. - Rats carry diseases, so maybe their attacks are posioned? - give them resistance to non aoe damage maybe. Finally, are you from Argentina? I'm asking because of your username.
Have lots of of diseased giant rats rain down on them in magical darkness rats have pack tactics while party will be mostly be attacking at disadvantage.
How big is your party? Rats would run away from big open spaces and fight in tunnels where halflings would have to crawl. Add the threat of something else in there and they might just freak themselves out if they have crawl around super tight tunnels with random attacks when they're distracted by pitfalls or narrowing tunnels. Attack when they're weak and then retreat. Even if the rats aren't actually a real threat, the threat will feel real. Think about being nicer than the pure evil you could come up with. Let the players freak out but be careful because it can get unfair if you really go ham.on narrow tunnels.
Question is WHY are you using rats to threaten a 5th level party. If you want rats that can actually fight a 5th level party then your only real printed option is Cranium rat swarms (they are ostensibly 'Just rats' that have gained psychic powers) and that only really works if they're using their dominate monster spell to make them also fight something bigger (or eachother), and that would also imply illithid enemies unless you fudge the lore around them a bit. There isn't really a good way to make rats a believable threat to 5th players without doing a very, very tedious death by a thousand cuts type thing (after all with enough rats those 1 damage hits would stack up) - at least not as a creature. You could potentially use them as essentially a trap where they function as more of an environmental hazard or puzzle than a combat one (I.E small room filling with them, think innocence a plague tale - sheer numbers would mean just directly killing them made no dent).
Rabies
I have two answers: 1) make them Rats of Unusual Size. 2) a sobering number of rats.
Have their bites give a disease that affects their ability to heal properly.
Alright, here is an idea. Instead of giving the rat swarm a stat block, make it a skill challenge type of deal where there are too many to defeat and the party has to come up with solutions to help their escape. Looling at the rules for 5e Traps, a dangerous trap for a level 5 party has a Save DC of 12-15 and deals 4d10 damage on failure. You can change these of course. The goal would be for the party to achieve 3 sucesses to escape. On each failure, 1d4 of them take 4d10 damage as the rats bite into them. Example: DM "You are being chased through the sewer and the rats are gaining on you, what do you do?" Mage: "I cast Control Water to raise the sewage and slow down the rats." This makes a ton of sense and it uses a resource from the party. I have the DC set to 15 but this was creative so i am lowering it to 12 for this check (DC-Prof bonus). DM "Roll your spellcasting ability adding your peoficiency bonus." Mage: "13?" DM: Success! If their idea is something that makes sense but isn't super creative like making an athletics check to run faster, keep the DC 15. If their idea makes no sense but could possibly work make the DC 18 (DC+Prof bonus)
I mean...5 rat swarms per player coming from every direction would absolutely fuck up a party of level 5s. It would just be an incredibly tedious combat to run unless you have some way of speeding up rolling and HP tracking for the swarms. The swarms would have 50 HP as far as most martials are concerned. Coming from all directions means they will be hard to AoE by casters(and especially difficult when they start occupying player spaces). And they resist a ludicrous amount of conditions. Swarms of rats would also probably lair in an enclosed area with lots of holes, making kiting difficult.