D&D 5E Encounters for 4 10th level characters using CR1s

[Oofta]

I agree that the premise is a bit off. That and 8 CR 1 monsters against a party of 4 10th level PCs is an easy encounter. If you ignore the multiplier for the number of monsters (I do, the calculation seems to work better) even doubling that number only gets to a hard encounter.

In any case, a couple of people have had a few ideas, but think a simple solution is quicklings. Run in, throw daggers, run away. They have speed of 120 feet, 3 attacks, evasion, attacks against them have disadvantage (they already have a 16 AC). Depending on terrain, with a +8 stealth check they take turns sneaking up, attacking from multiple directions and then run away.

So 3 attacks with advantage, difficult to damage. Individual hits aren't going to do a lot of damage but odds are you're looking at at least 2 hits (they're +8 to hit before advantage) if half the group target a single individual that's probably around 64 points of damage per round. Maybe do a blitz attack with all attacking every other round.

So zip in, take out a single PC, zip out while laughing from the darkness. Since they're tiny they can hide just about anywhere. Assumes you aren't on a sunny day in an empty parking lot of course.

 

[overgeeked]

I think you missed this part of the OP:

"so we want encounters with special synergies, traps, weird terrain, etc….anything that would make these CR1s a credible threat to this party."

You seem to be assuming the opponents just stand their and get smacked around. The question is about setting up an unfair situation and seeing if the 1 CR opponents can withstand the onslaught of the PCs. There are lots of ways a bunch of CR1 opponents could last longer than 2 rounds and lots of methods that would be more interesting than what you described. This is an exercise in being creative, so be creative.

Tucker’s Kobolds.

 

[CleverNickName]

How about....

6 Dryads: as described in the Monster Manual, except as noted below.

• These dryads are also equipped with longbows. They dip their arrows in the stagnant bog-water (a bonus action) prior to firing them.
• These dryads don't have the druidcraft cantrip, instead they have infestation.
• These dryads don't have the goodberry spell, instead they have healing word.

The dryads focus their longbow attacks on a single target at a time, starting with the first target to demonstrate magical ability. The dryads never end their turn closer than 20 feet to an enemy. If an enemy approaches within 20 feet, a dryad will use their Tree Stride ability to move further away on their turn, Disengaging if necessary.

2 Swarm of Quippers: as described in the Monster Manual.

Poison Bog: the battle takes place in a marsh full of stagnant, waist-deep water and tall diseased trees (the battlefield is considered difficult terrain, and all the trees are Large sized and 10-15 feet apart to let the dryads use their Tree Stride ability). The water is cloudy, and obscures the vision of any creature that doesn't have a Swim speed.

The dryads cultivate a rare and poisonous type of algae in this bog. Consequently the water is toxic, and causes a creature to gain the Poisoned condition for 1 hour (Con DC 12 negates) if it comes in contact with an open wound. If a living creature has less than full hit points, they must make this Constitution save for each round they are in contact with the bog water to resist being Poisoned. The dryads and the quippers are immune to this specific poison.

Underwater Pits: at a handful of locations around the battlefield, the dryads have dug out some pits beneath the surface of the murky water. These pits are 10' wide and 10' deep, and have hunting traps at the bottom that the dryads have scavenged from the poachers and trespassers who dare to invade their swamp. A creature that moves into a pit area will be submerged and need to use Strength (Athletics) checks to keep their head above water and/or swim out of the pit...provided they didn't get snagged by the hunting trap at the bottom.

Caltrops: In other locations around the bog, the dryads have placed caltrops in the muck below. A creature that moves through a square with a javelin trap must make a DC 15 Dexterity save or take 1 piercing damage (and must make a Constitution save to avoid being poisoned by the bog water.) Creatures that do not have a swim speed cannot see beneath the bog, and therefore make this Dexterity save at Disadvantage.

It probably won't be a TPK, but it will be a long time before the players ever forget this battle. The cleric is waist-deep in invisible quippers, the rogue is drowning in poison with his foot caught in a hunting trap, the fighter is puking and huffing back and forth chasing shadows, the wizard is getting peppered with a half-dozen arrows every round...

 

[Stormonu]

Would depend on the what spells the wizard has and if the party has a longbow, but I guess 7 Scouts with warhorses, sniping from 600 feet away in a vast open plain, just keeping the distance with the horses and slowly cutting them down.

Might take a while.

I was thinking something similar - a Goblin boss and 7 goblins riding on Dire Wolves. Attacking from different angles to minimize AoE effects. Half the group circles the party attacking from range while the other half moves in to trip targets and strike them on the ground before moving away and repeating. Using nearby woods or other cover to conceal their approach and cover their escape.

 

[Dausuul]

A labyrinth of tight corridors with 2-foot-thick walls, and 8 specters. The specters employ hit-and-run tactics; when the corridors force the PCs to spread out in single file, the specters swarm a PC at the end of the line--each specter coming through the wall, attacking, and leaving through the opposite wall, all in the same turn.

They organize these attacks so the first specter to attack (the one most likely to eat OAs and readied attacks) is the one with the most hit points left. They also prepare ambushes around corners, where the people at the back of the line don't have line of sight to the front of the line.

 

[Grakarg]

That would change their CR though. From the DMG (emphasis mine):

"Depending on the monster and the number of class levels you add to it, its challenge rating might change very little or increase dramatically. For example, a werewolf that gains four barbarian levels is a much greater threat than it was before. In contrast, the hit points, spells, and other class features that an ancient red dragon gains from five levels of wizard don’t increase its challenge rating."

Adding 5 levels of any class will increase the CR of a CR1 monster just on added HP alone. So that is not a viable strategy per this challenge.

Sorry my point wasn't clear. I'm talking about adding levels to a creature BELOW Cr 1 so that you raise them up to Cr1.
Like you take a regular goblin (Cr 1/4) and add some class levels to beef them up to Cr 1.
How much to beef up? Well, you have a Goblin boss at Cr1 to use as a guideline so... 6 HD, Multi Attack (typically Extra Attack kicks in at lvl 5), and a special ability Redirect attack. Overall the Goblin Boss is pretty meh vs high levels but he can serve as a template for how tough to make your goblin band. A rough check guess might be adding 3 levels onto a goblin and it might still be in CR 1 territory, maybe up to 5 levels (6HD and Extra attack range) depending on the class added. On the down side, it makes the encounter waay harder to run for the DM.
But still, a band of 8 goblins (2 groups of balanced parties) all with lvl 3 abilities for the sake of argument could be pretty interesting.

That said, I gotta give it up for the Quicklings suggestion. Those mofo's are just broken.

 

[Eltab]

Mix in a few Mephits who can blind the PCs, auto-hurt them with death bursts, mess up line-of-sight to ranged-attack allies, &c. Give the heavy-hitting monsters a better chance of surviving long enough to get in a second shot (such as a rechargable attack).