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

[Unwise]

Bounded accuracy does not make a level 1 guy a credible threat to a level 10. It just means that they are not completely irrelevant. It means that level 10 guys have to be wary of the city watch, not as individual guards, but as a group. It means there is no such thing as being immune to spears, just because a level 1 guy is holding them.

A group of CR1 monsters can chip a little of the level 10 guys resources, which is working as intended.

It is interesting to make the nastiest encounter possible given those parameters, but its not an issue with bounded accuracy if they fail to be a significant threat. I think the Cockatrice pack is the nastiest suggestion so far. You only need to roll poorly once to lose a character. Having even one person turned to stone is a pretty nasty consequence of a CR1 ambush. The PCs will feel the tension in that encounter I think.

 

[Grakarg]

Per the DMG a CR 1 creature can have up to 85 hp, and if you want to get creative, you could really tweak some strange critters within the DMG guidelines that would be a threat and could grind up some resources. Also, you can add class levels to a weak monster that would bump them up and can still be under CR 1 in the DMG. Like they are 8 goblins with 5 levels of Twilight Cleric or something annoying.

And there are the classic examples of this exercise (weak monsters absolutely wreaking high level PCs) such as Tucker's Kobolds or the Kobold encounters in Dragon Mountain. (all kinds of shenanigans like the kobolds drinking potions of invulnerabilty before the combat, level draining weapons, etc)

So... along that line you can have goblins each throw packets of Dust of Sneezing and Choking at the party. Or have some having drunk potions of firebreath, etc. Or have thieves attack the party, and have them use the 'Fast Hands' ability to 'Use an Object' and have them put manacles on different PCs. That could be a silly and fun encounter.

 

[Charlaquin]

Bad premise -- this isn't testing bounded accuracy because bounded accuracy is not about 8 CR 1 creatures being a serious threat to a party of 4 10th level characters (assuming they didn't all roll stats, nothing higher than a 6, and rolled hp and never got more than 1 per level, and also are all playing wizards with no combat spells).

What bounded accuracy means is that a CR 1 creature can be successful with an attack roll (not counting 20s) against almost all characters of any level. It's about the range of bonuses and target numbers, not if CRX is a great encounter for level Y PCs.

This. One of the benefits of this is that large numbers of low CR monsters can pose a meaning threat to high level PCs, and low level PCs can take on high CR monsters if they’re very careful and/or lucky, which wasn’t possible with the way attack bonuses and CR scaled in 3.Xe and 4e. It’s purely a math thing. It’s certainly possible to come up with a tactical scenario that makes that math irrelevant, but doing so doesn’t tell us anything about bounded accuracy.

 

[Charlaquin]

It's easy to make that challenge the PCs. All I have to do is make it the 10th encounter of the day!

Not necessarily. 8 CR 1 monsters is well below a Medium encounter for 4 10th level PCs, so even if they’re out of all their daily resources, it shouldn’t be much of a problem. Unless they’re also quite low on HP, which at 10 encounters, they shouldn’t be if they’ve used those resources wisely.

 

[dave2008]

CR1s tend to have around 30 hp or less. A level 10 full caster has 4/3/3/3/2. Cleric and wizard. A 3rd-level fireball is 8d6, for an average of 28 damage. A 3rd-level spirit guardians is 3d8, for an average of 13.5 damage. Drop both and whatever CR1 they hit is dead. A 10th-level fighter has two attacks and an action surge. She can drop four attacks in one round, almost certainly hit and deal an average of 42 damage from those four hits. A 10th-level rogue has one attack and can aim to guaranteed sneak attack for 6d6 damage (including the d6 weapon), for an average of 27 damage. And none of that assumes magic items. Two spell slots and two martial attackers.

Those CR1s wouldn’t survive two rounds.

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.

 

[dave2008]

Also, you can add class levels to a weak monster that would bump them up and can still be under CR 1 in the DMG. Like they are 8 goblins with 5 levels of Twilight Cleric or something annoying.

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.

 

[Shiroiken]

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

Emphasis mine on traps, because I assume the trap must enhance the monsters, rather than being the threat itself? Otherwise I can just make a trap deadly to a 10th level party...

Anyway, I think the most threatening low CR monster is the shadow. The strength drain is rough, more likely to kill than the damage is. The party must traverse a 5ft wide, 150 ft long passageway that has a rotating wall every 15 ft. The walls only rotate every 5 rounds, and only permit 1 character through at a time, which leaves at least 1 character alone for 5 rounds. Shadows seep in an out through cracks in the walls, picking off a lone character. With 8 attacks a round (as they can seep in and out, taking only 1 OA per round), even a high AC character is going to take a few hits. When the wall would rotate, they don't come out again until a character is alone (or in pairs if they figure out a way). Repeating this 10 times will be extremely deadly.

The only real problem is Turn Undead. If not by a cleric, you can have the rotating walls stop for 2 minutes after such magic is summoned (maybe the walls are being rotated by undead above the hallway), giving the shadows time to recover and return. By a cleric, it will destroy them if they can either see or hear the cleric. There are solutions to this too, but they get into the cheese range. The hallway could be blanketed by silence, preventing anyone from hearing the cleric, and beyond the walls might be magical darkness to prevent sight. With them coming out one at a time, the cleric could only get one with turn undead.

 

[FarBeyondC]

Don't know if I'd call a 'threat' to the party, but a team of 4 Rogue Quaddrones and 4 Meazels has a chance to be very annoying, especially at night or in dark areas.

Were the numbers not capped to 8, I'd rather do 4 Meazels and either 8 Drow Scouts (for night operations) or 8 Wood Elves (every other time) for the extra range.

Either way, the general strategy is to have the Quaddrones or Elves unload as many arrows as they safely can into the party (even at disadvantage, 16 shots should do something) outside the range of most forms of retaliation, then have the Meazels (each grappling a Quaddrone or 2 Elves) Shadow Teleport to safety.

 

[Asisreo]

Humans. Really any intelligent race. We're alot more clever than you'd think and with enough ingenuity, they'd be able to take out a clearly superior force.

The arena would have to be an Antimagic Zone. Disrupt the spellcasters and force a slogfest.

Split their party. Why take out the party of level 10 adventurers when you can just take out a single level 10 character? That alone changes the difficulty from trivial to deadly twice over. (Assuming Spies as the enemy).

 

[jgsugden]

I agree that this is not a tested of bounded accuracy. By placing additional restrictions on the encounter building, you're negating the stated premise.

However, if you want to talk about challenging a 10th level party with an encounter of (per book - no modification) CR 1 monsters with a maximum of 8 monsters, you're likely going to want deception in the situation, or encounter control.

A Pixie and a Dryad Watch the PCs from a distance, with the benefit of superior invisibility for the pixie and pass without trace for both, their stealth bonuses are +17 and +15. They wait until the rogue or fighter is on watch and then the dryad will charm them - silently - and invite them to go off and frolic. They offer up their Changeling friend as a suitable replacement for the guard duty, with the changeling in a suitable form to be a capable guard. Once out of earshot, the trusted dryad will instruct the PC to go with the pixie to see the dryad's treasures and joy, with the pixie casting fly on the rogue or fighter and then leading them up into the sky towards a nearby very highly elevated spot. Once the PC is 200 or more feet above the ground, and above a hazardous terrain if possible, the fly is dropped and the PC falls taking 20d6, or 70 damage. A rogue with a 14 con would have 73 hps. A fighter 84. Either would then by a valid target for a sleep spell which can be delivered during a surprise round. Once asleep, and without allies, either would be easy to finish off.

You now have a cleric, wizard and either a fighter or rogue still left in camp, asleep. The Changeling waits for the dryad to return with the equipment of the deceased PC, freshly cleaned, and dons the equipment of the deceased PC. The dryad then silently wakes the rogue/fighter that remains and a second pixie repeats the method of offing the first PC.

If the other PCs awake during the night, the changeling is there to put them at ease in the guise of the PC that was on watch.

You're down to a sleeping wizard and a sleeping cleric. Both are unarmored. Their ACs should be no greater than 12 (maybe 15 is a wizard has mage armor), and they're being attack with advantage in a surprise round. Assuming there is no mage armor, the wizard would be the target of the 4 shadows that attack in a surprise round, as they'd have the greatest chance of killing the wizard with the strength drain. With advantage, against AC 12 - You're very likely to kill that wizard in the surprise round, but if not you have a good chance for a few of those shadows to go again during the next round before the wizard and finish it off before it can rise. You could also have some

Shadows can attack silently, so there is a good chance the cleric did not wake up and that the rogue died in their sleep or before they could raise an alarm for the cleric. That allows the Changeling, 4 shadows and dryad to all do a coup de grace style attack and try to finish off that cleric before it goes. Right after those initial attacks, the 2 pixies hit the cleric with phantasmal force spells convincing the cleric that it is buried under a giant boulder and is being crushed by it, slowly. Intelligence saves of a cleric are likely very low. The wizard is going to lie there, trapped by the 'boulder' unable to see the shadows to identify them for purposes of determining a turn undead would be helpful.

You get a decent chance at a TPK.