Designing my first DnD boss fight with a giant mimic (5x lvl 5 characters)
Hello tabletop community,
I am designing my first ever boss fight, meant to really challenge my players. I don't want to kill any of them off since we're all new and it feels weird to lose a character, but I also want it to feel threatening. I could use some advice about how to execute this situation:
Boss is a big mimic disguised as a blood fountain with 6 long tentacle arms, each of which will be it's own figure on the board that can be up to 3 tiles from the 3x3 mimic figure.
Four of the tentacles have weapons that can deal 2d6 damage and have 30hp AC11 (roughly making it in line with a Brown Bear for threat and HP). They can grapple (squeeze the target) instead for 1d8 damage per turn, escapable on DC13 strength.
Two of the tentacles have shield-like hard points that defend neighboring enemies by giving disadvantage on attack rolls against them. AC14 HP30. I couldn't find anything to base these on for an encounter designer app.
Main body has low movement (10ft), and has 200hp AC19, and loses 20hp per tentacle lost. It has a bite attack +6 to hit 2d8. It also floods blood through sections of the room, forcing player movement and dealing 2d8 poison damage. I based it on a Roper for difficulty and attacks.
I think this combination creature would provide a very interesting and movement focused fight, but I'm very new to DM'ing and I'm afraid of accidentally killing the players.
My questions are: (1) How do I avoid accidentally killing everyone? (2) Is this fight too hard for a newbie group of 5 new players? (3) Any other cool ideas I didn't think of?
Want to know the biggest secret to being a DM? Even if you design an encounter poorly, and accidentally pick monsters a bit too powerful for your players... you can always just fudge the numbers a bit so things don't end in a party wipe. That's why the DM screen blocks the players' view of the monster stats and your rolls. ;)
And even if things go really really wrong, the party gets super unlucky with their rolls, and you get super lucky with yours, too much to believably fudge your way out of, you can always give them an out if you're creative enough and encourage some improvisation on their part.
So my advice would be to do exactly that. Don't worry too much about getting the encounter difficulty and balance exactly right at the outset. Way too many factors are at play when it comes to that, and even with a bunch of prior DMing experience, and knowing your party well, that's tough to do. But if you sense things going south for the party during the fight, just fudge the numbers a bit in their favor to make sure they don't all die. And if things go really really wrong for them, try to have a creative (and believable) backup plan to give them an out so the campaign doesn't prematurely end.
Edit: Or let them die, but then play the next phase of the campaign in another plane of existance. :P
Just for fun, the opposing perspective on fudging from the Alexandrian.
Eh... I've read that before and I don't think it's necessarily the "opposite" perspective. IMO fudging has its place, even with experienced DMs and players, but it's especially useful for new DMs with new players since just telling new DMs, "design your encounters/campaigns better" isn't super helpful in most cases. But yeah, I do largely agree with the author that being creative, and being open to and encouraging creative roleplaying solutions from your players is more ideal, which is why I mentioned that too. :)
That is a totally fair perspective. Completely agreed that for new DMs, it's basically unavoidable.
What I like the most about the Alexandrian is that he's not saying "never, ever do it" so much as "every time it happens, take note and recognize that something else has gone wrong somewhere."
A few things to consider.
The roper is a CR5 monster, which roughly means that it's balanced to fight four level 5 PCs. Your boss has more than twice as many hit points and the tentacles do damage (the roper's don't.) That's probably okay if the PCs are coming in just after a full rest, with full HP and abilities.
You mention neighboring enemies - are there minions in this fight other than the tentacles? If so, look carefully at the action economy.
Speaking of action economy, how is it structured? Do the tentacles get their own turns, are they acting on legendary actions, or are they part of the mimic's turn? (Those are generally in order from most to least difficult, from the PCs' perspective).
I love the blood effect. I would make it a lair action and give the PCs a way to counter it (an easily-unblocked drain, perhaps.)
Think about your players' average HP and go based on that. A level 5 cleric probably has about 38 HP, meaning they can survive for about 3 rounds of tentacle attacks if they get hit by the blood effect twice. That seems about right to me.
Regarding actions, I was going to have all tentacles take their turns with the mimic. This was a way to spread out the damage among all PCs and give everyone a target to wrestle with.
Overall I think the balance sounds pretty good. I'd brush up on the grappling rules so you have them down pat in the moment. Have fun!
You could give them the same ability as the paladin's Protection Fighting Style (PHB page 84). A dynamic use of these tentacles could be: Use Disengage to move the Protection Tentacles towards Attack Tentacles in threatened positions, then use their reaction to protect the Attack Tentacles as they move to grapple/attack vulnerable characters.
You need to make it very clear to the players that hurting the tentacles also hurts the main body. The first time they land a hit on a tentacle, have the main body wince in pain. Whenever they destroy a tentacle, have the main body scream in fury and spit blood. On the flip side, some spells (illusions, charm, etc) should probably only be able to target the main body, not individual tentacles.
By the way, are the tentacles burrowing? Otherwise, you may want to come up with an explanation to why only the tips of the tentacles can be hurt. It could be something as simple as; everything except the tip turning hard as stone immediately after moving into a new position. That sounds like something a giant mimic might be able to do.
Sounds like an interesting encounter. :-) Best of luck running it!
One thing to understand is that designing and balancing encounters in dnd is an art, not a science. I have a lot of spreadsheets and formulas that help me figure out if an encounter is balanced, but at the end of it I have to trust myself that I know that the encounter is balanced. The more encounters you create the better at creating them you'll be.
Quick edit: I will note, the one less vague thing I can tell you is that PC power does not scale linearly. The party's damage output roughly doubles from level 4 to level 5, so the offensive power of your party is probably higher than you're expecting it to be. Martial Characters get access to Extra Attack and Casters get an extra die of damage on their Cantrips, and get access to 3rd Level Spells.
I have never DMed, so I'm only relaying my experience as a player, but I'd like to share something our group's DM does with his D&D games. We play by "Souls rules". When you die, you drop all of your current level's accumulated EXP where you died, which he marks on the map. If you can make it back there, you get it back. If you die again before you get it back, they're gone forever.
He has designated safe "bonfire" places on his maps. If you die, you go back there at 1hp, and you can full heal there--at the cost of respawning all the enemies in the area. If one person dies in a boss fight and they want to rejoin the fray, it won't be easy because if they want to heal up and get spells and resources back, they'll have to spawn a bunch of enemies between them and wherever the party is. That could make it difficult to reach them, and also, make it difficult for the party to get back to the bonfire if they need to do so! I'm pretty sure that using the bonfire also makes all the enemies stronger each time but it's been a while since I played and I was on the outside looking in, would be better if our actual DM was explaining this, but you're stuck with me!
The thing I like about this ruleset is that death is not the end of your character, and it isn't so much a thing to fear as it is a strategic challenge.
That sounds terrible design in a ttrpg to be honest.
What would happen if one of the team members dies and not the others... how visually the "possessions" including xp are represented and why the rest of the team cannot take them with them back to the bonfire? I am seeing so many "immersion breaking" aspects here that I am not even wanting to think of the rest of complications.
Well I can tell you what happens in that situation because it happened to me! Cut off from the others, I healed at the bonfire and respawned the goblins outside who we had killed multiple times. They are the same creatures, trapped in the same looping nightmare world we are, so one of them recognized me. They were also designed for 1 person to be able to defeat, even if scaled up a bit. I used a Thorn Whip to grab the one that screamed and ended up rolling an intimidation check to get him to stand down. After killing the others, I went back to the cowering goblin and offered him the chance to join me in exchange for power. Seeing the remains of his friends, he agreed.
This is the beginning of a sort of legendary story in my friend group of my son, Four the Goblin. He's dead now and his soul lives in a ring on my finger, occasionally screaming into my mind. One of my own party members killed him and though we never finished that game because work is a bitch and life is chaotic, I fully intend to finish the elegant backstabbing I have planned for said party member, should we ever pick those characters up again.
As for stealing each other's possessions, I think we all just sort of agreed that no one would try to take the other's souls/exp. No other possessions dropped upon death.
It's very video game - or very World of Warcraft in particular though I'm sure it isn't unique to WoW. I'd hate it in a TT. But I don't dungeon crawl and this feels very dungeon crawly