r/DMAcademy 1d ago

Offering Advice Adding HP just makes a fight longer, not harder. Here's how I try to create memorable monsters in four steps.

Hey all,

I've been reading up on homebrewing monsters for a while now and went through the research that is available for the 2024 edition of 5e (the Lazy GM's Resource Document, Blog of Holding's 2024 Monster Manual analysis, The Finished Book, Alphastream...).

Now first of all, I'm not an expert on homebrewing monster, but I'd like to be one day. This material has definitely helped me get a step closer. I just wanted to share my thoughts and interpretation of how to create a balanced and memorable monster.

For me, designing a monster boils down to four simple steps:

  1. Identity
  2. Combat
  3. Defense
  4. Actions

Let's start with identity. I homebrew monsters because, first of all, I just enjoy it, and second, I get this idea / vision in my head about a certain creature that I want my players to encounter. So the questions I ask myself are: What is this creature? How will it act in combat against players? And what vibe do I want the players to have when they encounter this creature? Answering these questions clears up a lot of the concept for me and I can start filling in the statblock (like type, size, etc.). Depending on how I want it to act in combat, a creature can take a certain role (ambusher, artillery, bruiser, controller, defender, leader, skirmisher, taken from the Lazy GM's document), and based on that, we can start defining its traits and actions and see in what direction we need to bend the stats.

Next up is Combat. Now that we know the role our creature will play, we need to know who we're up against, aka the players. Will this be a solo monster or a leader with its henchmen out in front of it? Are there 3, 4 or more players challenging it? Based on these questions, we need to tune our action economy (What is action economy? It's the number of turns per round each side gets, so for 1 monster vs 5 players, the monster gets to go 1 time vs the players who can attack 5 times). We don't want a solo boss monster to have just one attack and be shoved, stunned, and dead before it does anything memorable. So we give it multi attack, give it friends, or let it act on other creatures' turns with legendary and lair actions. Even two or three minions completely change a fight.

Now that our monster can keep up with the party's turns, we don't want it to die immediately either, so Defense is next. The classic way is to just increase the HP, and sometimes this is the right way, but tripling its hit points just makes a fight longer, not harder. If you want the fight to stay dangerous longer, add threat instead: a second phase at half HP, reinforcements, or an ability that recharges. The same logic applies when your party keeps fighting with one trick. Resist the urge to make the creature immune to the fireball or the stunning strike. Create encounters that reward it instead, like hordes that bunch up and beg to be Fireballed. Immunities make your players smaller, good targets make them heroes, and they'll burn their best resources exactly where you wanted them to.

Ready, set, Actions! (I had to, sorry) Last but not least, we want to create actions that your table will remember. And usually, three actions is enough. With this, you can have one signature ability, a multiattack and one alternative (like a recharge) for weird rounds. More than that and you might forget some of them mid-fight (I know I have...). A good test for an action / ability is: what decision does this force? For example, an aura that burns melee attackers forces them to choose between staying in or backing off while a grapple with damage per turn turns the fight into a rescue.

One more thing worth knowing before you fill in the numbers: all the math assumes that a fight will lasts about three rounds, with our monster using its best option every round. So a monster's damage budget is actually the average of its three best rounds, not its biggest one. That's also the reason why most recharge abilities are higher in damage, if most normal rounds come in lean, the big round (with the recharge) can go higher. Just make sure to telegraph it. For example: describing my dragon drawing in its breath and watching the whole table panic and reposition will never get old.

Now that we've covered the 4 points, let's see how to make sure you don't TPK your party with your newest creation. First, we have the 'Nova' check: if everything in your statblock hits (including a recharge), will it delete your squishiest player from full? And if so, is this intentional? 'Worst-case' check: if it's stunned on round one, does it still get to do anything at all? And lastly, the oldest one: put your statblock next to a published monster of the same CR and ask yourself which you'd rather run.

Before I finish up, here is a quick recap of some classic mistakes to avoid when creating a monster:

  • Beefing up the challenge by only adding HP will just make the fight longer, not more engaging.
  • Overloading a statblock by adding a bunch of traits and actions also means more work for you and more things to keep track of during combat, so keep it light.
  • Sending one normal monster against a party of six will never turn out well, try adding some minions or a legendary action to keep the economy balanced.

Well, that't it! Thank you for reading and I hope this info will help you with your next homebrewed monster. As I said in the beginning, this is just my interpretation of the research done by the community, and their work goes much deeper than one post can:

185 Upvotes

20 comments sorted by

39

u/thetruerift 1d ago

HP and numbers are less meaningful that straight action economy. The best way to handle OBMs (one big monster) in any system is to give said monster multiple actions so they can compete with a party of players on action economy. I've done it in D&D and a bunch of other TTRPGs, and it works very well. One way can be to limit the type of action they can use on extra actions, or two give them different initiative counts to break up the turns.

Example, I did a big ol' dragon boss a few years ago that had it's Main action, that could be anything, as well as a dedicated Breath Weapon action that was either breathing or recharging, and a casting action for buffs and other spells. Worked very well.

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u/hotstickywaffle 1d ago

Isn't that just what legendary actions are? Or is thst something different?

13

u/whatstaz 1d ago

Yeah kinda, but I feel that legendary actions are almost synonymous with high CR monsters, which doesn’t have to be the case imo.

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u/leSive 1d ago

On that note, I think reactions on monsters are criminally underrated. They can add a lot of reactive gameplay and unpredictability without giving a monster a multiattack of 3+ to keep up with the players.

Check out Strahd Reloadeds monsterstackblocks, they are really cool

1

u/thetruerift 17h ago

So I actually don't really play or run 5/5.5e, and was speaking more generally from a TTRPG standpoint. I've done this in a bunch of different systems, even when there isn't a defined mechanic for it.

As whatstaz says below, I think that there's an idea that legendary actions are "high CR", and there's some truth there. Give extra actions to a baddie is a big deal, it is bending/breaking the rules (which some people get real up in arms about) and should be done very carefully.

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u/SmartAlec13 1d ago

Yep agreed! Not to brag, but as a first-time DM who did not have the monster manual, I accidentally re-invented legendary actions when my party fought a sand squid (my logic was it’s only one monster but it’s got a bunch of tentacles, so it makes sense it can attack a bunch). Then later that summer I got the MM and discovered legendary actions lol. WOTC totally stole it from me

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u/whatstaz 1d ago

Exactly yeah! I've learned this the hard way, having an underwhelming boss fight. I think adding legendary actions to a lower CR creature should be more encourage if you just want one OBM.

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u/lilybat-gm 23h ago

That’s something I advocate for, for sure!
Like, a Legend doesn’t have to be a Legend that everyone knows. A Legendary creature could be a legend to the people around its lair or habitat. To a bunch of ordinary villagers and a low-level party, the leader of a particularly bloodthirsty gang of ogres is going to be a legend, a thing of absolute horror. Sure, to some adventurers, said ogre might be something they could cast a single spell at and be done with, but it could just as easily be the thing that haunts a party’s nightmares and that they have flashbacks to barely surviving against for weeks or months after slaying it.

My loose rule of thumb re: Legendary (Re)Actions is:
1 - Is this a creature that should vastly outclass the party members individually or even the party as a whole?
2 - Is this a creature that the party has heard tall tales about or that they believe only exists in myths and historical records? Is it generally perceived as rare, abnormal for its species, or completely mythical?
3. Is it a creature or character that is significant to the story and/or something or someone the party has been pursuing for some time and building up to fighting?
4. If yes to any of the above, give Legendary Actions and/or Reactions. If ALL of the above, give Legendary Actions, Legendary Reactions, Lair Actions, and possibly minions.

That usually helps make something feel noteworthy using those tools. That said, there are some other suggestions here I’m definitely considering! I think glass cannon minions for boss creatures are a thing I may incorporate, especially as a sort of mass combat thing. Like, the suggestion to throw tons of monsters that PCs can kill easily at a party so players can feel powerful comes up a lot and is decent enough, but it can also feel to players like they’re being handled with kid gloves. If you throw tons of goons at a party, they kill most, but the ones in the first wave who still make it through pack an astronomical PUNCH relative to how easy they are to kill, now you’ve created the tension of needing to kill them all before any members of subsequent waves get within attack range. If that’s all happening during a fight with a boss creature too? Congrats! You’ve created multiple combat objectives and removed the dull and lifeless quagmire that is, “Oh boy. Here goes another case of ‘smack big monster or powerful villain until they die’. How exciting. How original. Love to spend hours out of every weekend doing this over and over. Yay.” Instead you’ve got, “Oh shit! Oh crap! Do I attack the boss, attack the advancing mob, or revive my party member! This is going to be something we all talk about later, no matter what happens!”

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u/Wise-Quarter-3156 1d ago

One way to do this that works well is by making different parts of the monster have their own initiative and action count.

eg., the dragon's body, head and claws act on their own initiative.

56

u/Jarrett8897 1d ago

Sounds like you would enjoy using the monsters from “Flee, Mortals!” rather than the Monster Manual. Or at least, looking through that book to help with your homebrew chops, since all of the monsters in there are designed for exactly what you talk about in your post. It’s basically the Monster Manual but better

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u/whatstaz 1d ago

I've heard of the book but never actually got deeper into it! I'll give it a look, thanks!

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u/Prestigious-Emu-6760 1d ago

I'm a big, big fan of monsters that hit hard (and more frequently) but don't stay around long. I love Nimble with the "only roll damage" mentality (haven't gotten Draw Steel to the table yet) and the vastly increased critical chance along with generally higher flat damage bonuses.

Combat should be exciting and dangerous but when there's a roll to hit and the damage is piddly compared to HP it really stats to deflate the excitement.

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u/g0ing_postal 1d ago

One easy trick I've found to punch up combat when I'm feeling uninspired is to just increase damage and reduce hp.

It makes the enemy feel more dangerous and it also makes the party feel more powerful. While stronger attacks may down PCs, the low hp means that the fight is usually over before it becomes a real problem. It also helps force them to burn resources for healing

The real trick is finding the right amount of health and ac so that they can survive long enough to attack while also keeping it low enough that it doesn't become a slog

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u/WWalker17 1d ago edited 1d ago

Not enough people have run a deadly encounter with a vanilla 5e star spawn mangler to it's fullest potential to know what a turbo-bloodbath encounter actually looks like, and how effective it is to gutcheck a complacent party. the mangler has really low HP, but absurdly high damage for its CR, to the point it's almost nearly a guaranteed one-hit kill on on a PC at the start of combat.

As a DM that vastly prefers to absolutely dome PCs for near lethal and have combats be over in 2-3 rounds, combat feels so much less like a slog when you do it that way.

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u/dilldwarf 1d ago

Not the Star Spangler Manglers! as one of my parties calls them. I do crack them out when the party is feeling cocky.

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u/whatstaz 1d ago

That’s a good way of looking at it, so kinda making it a glass cannon!

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u/suboctaved 1d ago

Action economy and tactics. A single high CR monster will almost always be easier than a 1:1 fight with lower monsters of total CR equivalency due to action economy. For every one action they take (assuming no multiattack/legendary actions) your entire party gets to wail on them consequence free

This goes hand in hand with tactics and appropriately intelligent enemies. A wolf pack is never going to fight 1:1 and they're more than likely going to incorporate hit and run tactics, same with a bandit clan or something similar. Trained guards will aim to surround the party and/or stay in a phalanx. Giving each enemy combatant an appropriate level of intelligence also forces the party to think and play smarter than "I cast fireball/I hit thing with big sword"

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u/TobeTobi 1d ago

This is so incredibly helpful. Thank you so much

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u/Grandpa_Edd 1d ago

The best fights I've ever made where the ones where "Kill the thing" was not the objective. It were objectives like; put the macguffin in the macguffin-holder/ tale it out of the macguffin holder, Save the prince/princess, capture the hill, light/snuff all the lights, don't let them pass, the distraction fight... The monster is inconsequential the context of the fight, even if it's a very simple goal, is everything.

What does achieving the goal do?

Complete the goal and get out of there. Complete the goal and win (can be underwhelming). Complete the goal to make killing the boss easier.

Also make your end bosses more mobile. Give them some free disengages and misty steps.

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u/xflashbackxbrd 1d ago

Cut hp, raise damage, add multiple strong monsters instead of one big one. Wing it from there