[RPG] Do 5th-edition D&D PCs consistently outmatch level-appropriate encounters


I have a group of PCs that started at level 1. The group varies in size between 6-8 PCs and they have a good spread of classes (healer, tanks, damage dealers, 2 arcane casters).

They are level 5 now. I have found that they are consistently able to handle encounters whose xp total should be considered "deadly" to my group per the DMG.

In general I have been estimating the compensating factors and difficulty of the encounter, not calculating it.

The last adventure was when the PCs were level 4. The adventure day took them through 5 fights with 2 short rests and no long rests. There were 7 PCs for this adventure.

1st fight 4 CR2 monsters + 1 CR4 monster. Total XP 5800

2nd fight 1 CR5 monster: 1,800 xp

3rd fight 1 CR5 monster: 1,800 xp

Short rest.

4th fight 3 CR 3 monsters, 12 CR 1/2 Monsters: 8,100 XP

Short rest.

5th fight 1 CR 8 monster, 3 CR 3 monsters: 12,000 XP

Total XP for adventure: 29,500.

I found the challenge of this adventure to be too small for the team. In particular I had planned a story mechanic to save the PCs in the final fight but was surprised to find that the mechanic was not necessary as they ended up besting that encounter.

Some things I have noticed which seem unbalanced are the damage potential of certain classes compared to monsters. PCs just seem to do more damage. Also the feat shield mastery in a large group of PCs is quite effective because imposing the condition prone (thereby giving other melee advantage on attack rolls) allows the PCs to focus threats down very effectively.

My questions.

  • In your campaign do you find that the PCs are strong compared to the CR/XP
    ratings of the encounter?
  • Would it help if I stopped estimating the CR of encounter and stuck
    to the DMG more rigorously when designing encounters for my group of
    6-8 PCs?
  • Am I correct in assuming that the CR ratings for monsters as given
    will not provide a significant challenge to the PCs going forward
    beyond level 4 and 5. Will I need to increase the power level of the
    monsters, or make other things like terrain to not be in their
    advantage when designing encounters for my group of PCs?
  • Is what I am seeing a function of adding additional PCs beyond the
    first increases the power of the party in a non-linear fashion or
    more a function that the PCs work well together?

Best Answer

All D20, but DnD 5 especially, are designed and balanced assuming a 4 or 5 player party. And you can kinda tell, when the rules start asking you to apply multipliers to bigger parties, rather than giving any concrete guidelines. Assuming distributed player competence, a 6 person party isn't simply 20% stronger than a 5 player party. It's much higher. There's an entire additional PC, with their own suite of abilities, magic items, and most importantly, actions. Never underestimate the power of having more standard actions than the other guys (unless you're a pack of CR1/2 minions going up against a bunch of level 5 adventures, then you're screwed either way).

In short, designing challenging encounters for big parties is one of the more substantial challenges a GM may have to face. There seems to be a razor thin design space between "no actual danger" and "guaranteed TPK" when planning for large parties. My own personal strategy is "5 players per party max unless you have a super good reason that a sixth needs to be in this particular game, and never ever ever ever more than that (and preferably not 6 for long)," but that probably won't help you, specifically.

First of all, stop giving them one big thing to focus on. There are a couple iconic encounters that tend to necessitate one big monster against a party of intrepid heroes, like dragon slaying. The problem here with big parties is 1 creature generally can only attack one thing at a time, so even if the beastie is downing 1 PC a round, the rest of the party can pop cool downs and beat the timer. If you design the combat space so the beastie can use it's AOE abilites to good effect, you often find yourself looking at a TPK. Quantity may be a quality all it's own, but it isn't everything. Basically, when the party is that big, the single monster encounter HAS to be able to one round KO any given PC, or it's not a threat. And while it's killing one PC a round, the remaining party members HAVE to have a DPR high enough to whittle the beastie down before it kills them all, or they all just die. SO! Anytime you're tempted to let 7 or 8 dungeon crawlers dogpile one big boss monster, resist the urge. Instead of fighting one wyrm, why not a mated pair of adults, maybe with a wyrmling thrown in to harass the squishies? (Actually, this particular piece of design advice sort of holds true for any size party if there's more than one healer to keep the front liners standing)

Secondly (related to the first), if your party outnumbers the monsters, they'll probably win unless each monster is SIGNIFICANTLY stronger than the PC. I can't give concrete CR equivalencies because it's different at different power bands, but 7 lvl 5 PCs who know which end of a longsword is pointy should mop the floor with 5 CR7-8 monsters. The power of two players worth of extra actions is too substantial to ignore. Design the encounter using the guidelines in the DMG, then add a few support casters or bowmen(or bowwomen, or bowgoblins, or bowwhatevers) at a little under CR to bring the numbers within 1 of the party.

Finally, if you're going to do mob (mob in this context being a large angry group, not a MMO enemy, nor a crime family) encounters, consider looking at the minion style monsters from 4th edition. They had decent defenses and attack bonuses, but 1 HP and very low damage. Custom brew up something mob-able, maybe give them advantage for being adjacent to allies, with a decent attack bonus and a beefy AC, but a damage range of a d3 and very low health. And remember, mob fights aren't typically meant to be challenging in and of themselves, they should be hard enough to drain some resources while letting the players feel like badasses for steamrolling through a pile of enemies. Remember, damage spread to 7 players hurts a party much worse than that damage stacked on 1 or 2 frontliners.