A monster's healing ability can be an interesting puzzle, turning a typical fight into something a bit more interesting (like a Troll's regeneration)

I made a homebrew monster that was like a huge sea-anemone that healed as long as it was attached to the ceiling.  The players were immediately excited and terrified when I announced it was healing for the first time, and I made sure my description of the healing made it clear that it was drawing energy from its connection to the ceiling.  They scrambled to sever it's tentacles, disabling its healing feature, rather than just attacking it directly.  It added a unique dimension to an otherwise straightforward battle

The one healing thing I do is that I give bosses a legendary action to consume minions to restore hit points. It keeps the boss in the fight without slowing anything down because the players are still taking out minions

A few people have pointed it out but it generally is less a balancing feature and more so a flavor bug. Animals and non-humanoids in the environment traditionally develop physical resistances that humanoids need to utilize their intelligence to bypass. Look at an alligator and the affectionately nicknamed "sleepstick" that people need to use to penetrate their skulls.

The trouble is I think designers (DMs honestly) don't do the math because it's very durtly and just look at hitpoints and power. So on paper the enemy is "scaled" (badum ts) because the numbers look right; however when you go into practice you realize the opposition has damn near double health but can't kill anyone effectively because the players aren't necessarily doing the damage that they need to. In my practice i will heavily alter an enemy(s) health depending on their damage chance and perspectives life-length especially in combat.

My favorite enemies were enemies i designed puzzles around (for my players too believe it or not) where constructs had minimal health pools but absurdly high AC. The catch was they had a gem in them and if you were to ascertain the location spells are not limited by AC so targeting that area with a spell or hitting hard enough in that region would actually damage or straight up destroy the gem causing the first nightmare encounter they had into a very quick and satisfying combat puzzle they could solve on the fly and became a relief later when fighting more standard enemies they could split the party's focus on.

I never thought about regeneration that way before, but that makes total sense.  For it to be fun, it should be a puzzle.  Or, you can't hurt the badguy unless you meet X condition.  Although, I guess winning sub-optimally is itself part of the gameplay, lol.

8:30 I ran a monster very similar to this in my last game (Note: I also designed many magic items and prosthetics to buff my players, if this seems a little strong). Basically, the idea was that it always had its turn last in the initiative order, and had a maximum health of 100. For every ten damage it received in the round leading up to its turn, it would gain one action on its turn. Obviously, it would use these actions to attack, but then it would gain back ten health for every successful attack. One other thing of note, it also had the ability to be immune to immobilizing spells, but in return was unable to take any reactions, which I will mention in a second.

The idea going into the design was to make a monster that would 1. be more dangerous on lower health, and 2. be able to heal (in a reasonable way) to bring itself out of danger, thus making it less dangerous. As for how I expected my players to defeat it, I figured there were two strategies they could use. Either 1. They would put their highest AC character in front of it to absorb actions and deny it healing, maybe plink-plonking it from the back, or using a hit-and-run strategy. Or 2. going in for riskier, higher damage attacks to burn it down before it could take its turn, trying to spread its focus between the party as to prevent any single player character from taking too much damage.

Now, I want to mention that this was, by far, not my players favorite designed fight. If I could go back, I would have told them about this monster in advance in game, offering some hints about how to actually beat it. The first time it healed back about 60 health in a turn, there was an audible groan from one player. The second time I used it, I used a visually similar, much stronger variant. Because the players were familiar with the mechanic, the combat went much more smoothly. If anyone has any thoughts on this concept, please share them, I would love to know what ideas you have on this kind of monster mechanic.

I definitely see your point on healing (this is why I tend to use it very sparingly), but I've found that using resistances (and weaknesses) can carry the internal consistency of a setting and, at times, push players to get out in the world and do research ^^

Hey Mike, I might test out some variation of your 'monster heals at the start of their turn'-idea:

- Creature HP = their Proficiency Bonus
- Creature "Stamina/Regenerating HP" = their Proficiency Bonus x one of their Hit Dice

I don't know if it'll work, but the idea is the party needs to pummel this guy to get an actual hit in. If their stamina is zero when they're hit, they lose one hit point

Me too! My monsters have rarer, obvious, creature-type-wide resistances and weaknesses, and only ever restore hit points in special "boss" combats where the restoration of health is a key component to the encounter. The same concept exists in video games much of the time, where spending your resources "healing" yourself or your teammates only prolongs the battle, as does bolstering defense instead of focusing on your damage. "Regeneration" sounds pretty punishing! Certainly makes for a memorable puzzle-like boss encounter, provided your players are capable of the damage necessary within one turn. Would be fun to bring back later too!

I like weaknesses and resistances myself. I have split opinions on immunities but use them in drsigns when they feel right. Healing however frels like a feature that should be out of combat, for both players and monsters.

Killing a fire dragon with fire would feel stupid

Regeneration would be a great in world explanation for lazy hp tracking. 20 DMG in one turn kills the zombie, but if you don't make it, they regenerate back to full

I mean healing abilities generally should be tied to a resource, so if you have a healer in an encounter the players get to decide between killing the healer first, or powering through their resources.

The bigger problem with resistances is that the players often don't have enough ways to interact with it. A creature immune to non-magical weapons might leave a character with no options to fight it.

I kinda hate that fights only last 3 rounds on average. It usually doesnt give enough time for interesting interactions to happen.

Your issues with resistances seems to only be an issue with systems which have HP bloat.

If most foes go down in 1-2 hits, having them resist some damage types isn't as annoying.

That must be really confusing for older players when you run a troll battle.

I don't think I agree on healing. I think having a puzzle-like mechanic which heals monsters is worth having in some fights, it just has to be a puzzle which your particular players don't know the solution to like with trolls and fire. Plus bosses having a way to heal is a good way for DMs to have an in-combat way to rebalance encounters.

Resistances I see your point on. I don't think I would reduce their use, but having them be triggers absolutely sounds great and I'll probably try it out.

That whole assumption of hitting roughly 2/3 of the time always annoys me. In the campaign I’m in my fighter with 16 strength has a 50% chance to hit an AC 16 enemy. And in that campaign a LOT of enemies are AC 16. It’s frustrating.

I will say that I have a fond memory of damage immunities. In one campaign, I was playing a Wild Magic Barbarian at a fairly low level, I think it was 3 or 4. The DM threw several Wererats at us, but when they were prepping the session they completely overlooked that they have complete immunity to bludgeoning, piercing, and slashing damage from nonmagical, nonsilvered weapons. I didn't have anything that could hit the Wererats at all, so I was planning to just rage and grapple them until someone else could handle them. But then when I raged I rolled on the wild magic table like always...and hit the exact rage that I needed. The one that gives your weapon the light and thrown properties and - importantly - makes it deal force damage. Suddenly, my barbarian is now throwing their greataxe and dealing force damage, completely bypassing the immunity. It completely turned the fight around and it was a lot of fun.

Mike you just gave me bad ideas.
Now my players have to deal with resistance and reciprocal power up from the damage. Lol.

You could have the max HP reduce every turn the full heal happens, so killing in one turn is a lower hard DPS test until it's finally passed.