The Dungeon Master’s Guide describes the mechanics of how to create a stat block in 5th Edition, but is that really what you need to know to create a great monster?
I say no…you need know why to make a new stat block, and how to make sure it stands out to your players.
If you follow this how-to, your creatures will have a depth that mere numbers on a page cannot provide.
Sometimes All You Need is a New Hat
Do you have a party of experienced players that know the Monster Manual backwards and forwards?
Maybe you are short on time before the adventure, don’t have enough time for a complete custom build.
In this case, simply reskin something…if you need some sort of nightmarish beast, take your everyday Ettercap for starters.
Tweak it by describing it as some sort of twisted beast, say that its webbing is instead viscera, and there you go.
My players never figured out they were fighting an Ettercap, they thought it was something completely new.
Find the Flavor First
Figure out what reason is leading you to create something new. Do you need a lower level Celestial, a higher level Fey, or a beast for your player to polymorph into once they’ve reached a level where the conventional beasts have topped out?
These are all valid creations that the official D&D products lack. Firsr find whatever it is that you want, and distill that down to its core. What does it have to do that another creature can’t be reskinned to do? Once you know that, you can figure out how to put it all together.
Let the Flavor Show in the Mechanics
This can be done in subtle ways. If something slithers, make it immune to being prone.
Shake up the spell list, giving it a theme. Play with damage resistances…all of that stuff. Give them cool ribbon effects, which is to say, abilities that don’t come into play in combat.
If you’re making a rat demon, give it the ability to squeeze through spaces smaller than itself, and the ability to speak with small rodents. If it’s a cat-like fey, give it advantage on Acrobatic checks.
Even if those abilities don’t come up, it will inform your roleplaying of these new creatures.
Use What the Game Gives You
While making up your own abilities might be fun, keeping an even keel is important. Use the abilities that come with 5th Edition…don’t try to reinvent the wheel, especially when it comes to things that affect the creature’s combat abilities.
Crafting new combat tricks makes determining the Challenge Rating (CR) of the thing difficult to do, and thus makes your life harder when trying to create balanced encounters.
Remember the Chimera
No, I don’t mean the creature from the Monster Manual. In mythology, chimeras are the combinations of a bunch of animals into one form.
If you want a new creature, in particular a NPC, this might be the best option for you. Take a little bit from Table A, a bit from Table B, and something from Table C. Soon you will have something unique that your players will remember for a while to come.
Go Big, or Go Home…
Don’t be afraid to throw something big at your players. Have faith in their ability to deal with whatever they come across. Players are infamous for outthinking their Dungeon Masters, and figuring out ways to beat creatures they have no business killing.
Recently I had my group fight a solo Balor, and they killed it in a single round after our monk stunned it. For weeks they were fighting corrupted angels, and all my hard work was undone by the casters using Banishment to send them back from where they came from.
Trust in you pplayers, and make the fight ahead something memorable.
…But Always Have the First Run Done in Pencil
If you’ve never used your custom monster against live PCs, keep an eye out for how difficult the encounter is turning out to be. Feel free to make adjustments if things are too rough.
The easiest way to do that is to lower the amount of hit points the creature has. You can also pull your punches a bit, giving your overpowered attack a recharge that you never seem to hit.
Using a DM screen to hide your notes so you can fudge a bit is a must.
On the other hand, if the fight is going too easy, you can bump up their hit points or their AC. Be careful though as many players track that sort of thing, even if they do so unconsciously.
If their attacks that previously hit on a 16 don’t hit any more, or if the first creature died after fifty-five damage, and the last is still up at seventy, they are going to know you’re playing fast and loose.
Past is Prologue
If you have access to them, and you should as long as you can get online, look to older editions of D&D for inspiration. You can pull monsters that didn’t make it into 5th Edition straight up, or twist them to fit your needs. This is a great way to bring back those iconic monsters that were left behind in the edition shift, surprising and wowing your players.
Remember to Have Fun
Playing roleplaying games isn’t homework, and unless you’re really luck no one is paying you to write the game you are creating monsters for.
You have to have fun, or you’ll burn yourself out and never finish the campaign you’ve worked so hard on.
Mix it up, and make monsters you’ve always wanted to see in a game, be that a level shifted version of something that already exists or something from your favorite series. Either way, be sure to revel in the torment and fun your players will have.
With these tips and the guide in your Dungeon Master’s Guide, you should have no problem making creatures for your own home games.
Do you agree with my tips? Think I’m way off base? Have some of your own?
Please share them and your reasons why in the comments below.