Tips To Design Your Own Monster In DND

So, you’re running a game with more experienced players who already know many creatures from the Monster Manual. A beholder no longer scares them since they know what to do against them. Or maybe the creatures from the manual just don’t fit your homebrew setting. In any case, it’s time to make your very own monster to show your players what danger really is.

Though Dungeons & Dragons offers a lot of interesting creatures for you to use, it’s always enticing to have your creations on the battlefield. How do you do these creatures properly, though, without risking killing everyone or being way too easy?

Updated on April 23, 2024 by Lucas Olah: We’ve updated this list and added even more tips for creating your own monsters. With the 2025 Monster Manual available alongside the other core rulebooks, it provides an even easier opportunity to create the perfect monster for your campaign.

13

Determine Health Based On Its Traits

Squishy And Strong Or Weak And Durable?

The basic things determining your creatures’ challenge are their health, AC, saving throws, and damage. We recommend that their health be big if everything else is relatively low, but the better their stats are, the lower their health should be in order to balance things out. For instance, you should make their health lower if:

• Their AC is high (15 to 17 for low-level monsters, 17 to 20 for mid-level monsters, and above 20 for high-level monsters),
• Their attack and damage bonuses are high (regardless of whether they’re martial or magical attacks),
• If their spell list is too powerful,
• If their basic attack has multiple damage types or causes conditions,
• If they have resistance to a damage type,
• If they’re immune to a damage type or a condition,
• If their passive traits, Legendary Actions, or Lair Actions are too strong.

It is also worth mentioning that if your monster is meant to be high-level, it’s okay to stack a lot of those while still having a decent health bar. Just don’t make your monster good at everything; otherwise, they might be too powerful for the party.

12

What Is Your Goal?

What Specifically Do You Want To Accomplish In Battle?

An important detail when creating your beast is to think about what exactly you want from it. Is it a minion? A BBEG (Big Bad Evil Guy/Gal)? Is it supposed to be a powerful spellcaster? Elemental damage? Or do they maybe just wield heavy weapons and go berserk?

Analyze your creature and how it fits your setting and your game. If you want an evil wizard, for example, you can even start creating them similar to a playable character and change things from there or rely on one of the mage NPCs from the Monster Manual. Their place in the narrative you’re building will also help you determine what fighting style you want for your monster.

11

Mix Difficulty Up

Easy And Hard Work In The Same Game

Diving a bit further into the previous topic, a lot of DMs worry about making their games too easy or too hard. The thing is, it’s okay to mix difficulty up. Not every encounter needs to be challenging; some creatures are just not a threat to certain players, especially if their levels are high. But some creatures (like the BBEG) need to be threatening and even deadly.

It’s okay to make weak minions. One of them alone should be obliterated by your players, and you can control a minion’s difficulty simply by adding more of them to the combat. It’s okay to give them the satisfaction of an easy victory sometimes, so they won’t waste a lot of resources when they meet bigger threats.

Also, the party’s level should be considered when designing the difficulty. For example, a monster that has an insta-kill ability is too much for a low-level party, but once Revivify is part of your spellcasters’ repertoire, an ability like that is more tempting.

More often than not, players are unpredictable. It’s okay to make the enemy slightly tougher than you think it’s necessary; they’re multiple heads against just you, so they have a better chance of winning from the start. This tip doesn’t apply if you’re a veteran and your players are newbies, though.

10

Let Your Attacks Do Multiple Things

Make The Best Of Your Turn

When balancing monsters, especially when they’re high-level creatures, it’s crucial to let them do a lot of things with their abilities. After all, it’s one guy versus a party (unless you rely on minions), and though you can use things such as legendary actions (we’ll get there), your action economy is still bad compared to a whole party.

Thus, it’s okay at high levels to make an attack that causes multiple damage types, is easy to hit, and might trigger a condition, too. The 2025 Monster Manual even removed saving throws for most secondary effects caused by attacks, which, like it or not, increases difficulty. Add bonus actions that can trigger more effects, rechargeable abilities, and legendary actions, and your monster can be quite the menace.

9

Use References From The 2025 Monster Manual And Beyond

From Other Monsters To Different Media

Even if the Monster Manual doesn’t have a fitting creature for your setting, it has a lot of references that can teach you about making your own monsters. For example, if your creature is undead, you can give abilities that are common to these creatures, such as Undead Fortitude.

An easier way than starting your creature from scratch is to find something similar in the Monster Manual and adapt it. Remove abilities you don’t think fit your monster and add others that you can either create or even take from other creatures to mix and match.

It’s also viable to see a character whose abilities you really like from a game, movie, series, or book, and see if you can adapt these abilities properly in a D&D scenario, either by giving them official traits that are similar enough or just homebrewing your own.

8

Roleplay Your Monster

Different Creatures Have Different Battle Strategies

Difficulty doesn’t come simply from high stats and spells, as all these powers aren’t going to use themselves. You must also do your part when you’re doing the encounter itself. And controlling a beast is very different from controlling a person. For example, a low-intelligence beast will likely attack whoever is closer or whoever does more damage. However, if your players are fighting people, it’s okay to be smart about it. Is the tank with high AC that is also using the Evade action not getting hit by any of your attacks? Attack someone else, then. Is someone healing the party? Focus on them.

Use tactics that fit your monster instead of just attacking whoever is close to you. It’s also okay to roleplay the enemies’ emotions. Let them be arrogant if they’re winning or scared if they’re losing. Have minions care for their co-workers and focus on the guy who killed their friend. Or be terrified that most of them died, and have them flee. Emotional outbursts are great justifications for the enemy changing their behavior in battle, for better or worse.

7

Make Minions That Synergize With The Boss

They’re More Than Just Ugly Faces

You’re likely aware that minions make a lot of difference in big boss fights. You’ll get to do more attacks in a round, and whenever someone attacks a minion, they’re ignoring the boss, whose health is safe and sound. You can do better, though. Instead of just giving random pets for your boss, think about your boss’s abilities, the minions’ abilities, and how these two can make both characters deadlier in the process.

For instance, if the boss causes extra damage when they have an advantage, minions that can give your boss an advantage are more valuable. You can make minions who are constantly using concentration spells that buff the boss or even heal them, or the boss can make the minions stronger, give them an advantage, etc. Show your players how great these monsters work together.

6

Resistance And Invulnerability

Your Fireball Means Nothing To Me

Another good way to control whether your monster will be a challenge is its damage resistance, as well as invulnerability (or even vulnerabilities). A low-level monster will likely not have these things, but if you want to challenge your spellcasters, for instance, you can simply give a creature Magical Resistance or resistance to a damage type their spells rely on.

You can also make them invulnerable to certain conditions, such as being paralyzed, to avoid specific tactics like using Hold Person. Or these things can match your narrative; a creature made of fire will likely be immune to fire damage. Just don’t give a lot of those to the same creature. You can also balance things out with vulnerabilities; the fire creature used as an example before could be vulnerable to cold damage.

Thinking about the type of your creature is also an efficient method of balancing. For instance, Hold Person only works on humanoids, so if the monster is anything but that, they’re already immune to it.

5

Legendary Actions

Pump Up Their Action Economy

One cool feature monsters have that allows one of them to compete with whole parties is their legendary actions. They can do these specific things at the end of someone else’s turn, similar to a reaction, though marked separately.

You have points that you consume when using them, and they return to you on your creature’s next turn. You can use legendary actions of other creatures as a reference (there are many good ones) or make your own, though it’s something easy to accidentally go overboard.

4

Make Them Stronger In Their Lair

Home Sweet Home

You can also use lair actions along with your legendary ones. They are separate traits or buffs a monster gets when fighting in their lair instead of, well, anywhere else. Similarly to legendary actions, you can get references from other creatures or make your own.

The fun part about lair actions is that, even if the party has already fought the BBEG before and knows what they can do, you can surprise them with extra features and traits during the actual main battle against the villain.

3

Poke Your Players’ Weaknesses

Hit Them Where It Hurts

For deadly encounters, you can always check what your players are bad at and make creatures accordingly. If most of your players have low Wisdom scores, then a character capable of using mind control spells will be a big challenge for them, for example.

Just don’t do that all the time, as you should also let their strengths thrive. If a player has fire resistance, you should still use fire attacks. Otherwise, your player took that for nothing. However, your BBEG can learn from experience and use things they know the party is bad at dealing with.

A fun thing to do if your players have unique storylines and each has their own antagonist is to make their villains good against them specifically. Hunt your wizard with a character designed to kill spellcasters, for instance. Your party will be even more united to protect their friend after that.

2

Use Magic Items

A Challenge Spike And A Reward

You can hand your monsters magic items to make battles more intense and enemies more powerful. They can come from the Dungeon Master’s Guide, or you can create them as well, allowing some of the villain’s abilities to come from them.

They also work very well for rewards. After all, if the idea is that your players defeat the bad guy, then they’ll likely loot the loser and keep the magic items for themselves later on. So not only do you have a good way to increase their power, but also a nice reward system for the party.

1

Homebrew Traits

Experiment Everything

We’ve mentioned a few times throughout the article that you can use references for things such as legendary actions, abilities, etc., or you can make your own. Well, don’t be afraid to create your own abilities – the most unique thing you can offer your table is yourself. As great as the Monster Manual or fan content can be, there’s just too much to research if you want something approximate to what you have in mind. Instead, just get your idea and try to make rules that work within D&D.

You can use random encounters and fights that don’t have a lot of narrative importance to test these things. You can see if your idea is too easy or too hard, if it just doesn’t work, or how players will react to it. If your veteran players are confused about what the monster is doing, it’s okay to be upfront with your players and say that it’s a homebrew thing you’re trying. They can also give you feedback on whether they think your idea added a nice challenge to the game or if it was just annoying.

Honorable Mention: Don’t Forget; It’s Not You Vs. Them

This point was briefly mentioned earlier, but it’s a very important one. You, the DM, are not the villain the party will fight against. You’re the game they play. That means playing the bad guy, yes, but games are designed to be beatable. Your goal is not to perform a TPK. That can and should be a possibility, but it’s not the ideal outcome.

After all, if you wanted to, you could easily make an immortal creature, immune to all conditions and damage. It’s an extreme example, of course, but the point is that if you want to kill them, you will – you make all the rules. So, don’t forget that the game’s goal is that the BBEG is supposed to be defeated, even if eventually. And when the players win, everyone wins, including you, for making the amazing story they lived through.