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Customizing Monsters

by Mike on 22 December 2014

The D&D Monster Manual is likely the most powerful tool we DMs possess and with a few tweaks we can turn the 300 monsters contained within it into a nearly infinite range of monsters to drop in our game. In this article we'll look at different ways to customize the monsters in the Monster Manual to fit nearly any scenario.

This article borrows heavily from the "Creating a Monster" section of chapter 9 of the Dungeon Master's Guide which is definitely worth a read. It's a great toolbox for building and customizing your own monsters.

Let's look at some lazy ways to customize monsters.

Call It Something Different

The easiest way to customize a monster in the Monster Manual is simply to describe it differently. We can do a whole lot to shake up monsters just in our descriptions. Reskinning monsters is likely one of the most valuable tricks we DMs hold. Often we can do so with no mechanical changes at all but if we want to add a feature or two, we can often do so right in the middle of our game without writing anything down. With description alone every orc, goblin, veteran, or dragon becomes a unique foe.

Changing Weapons and Armor

For humanoid foes, we can change up weapons and armor to make them unique and fit a new situation. Many times we can do this without changing the mechanics. Just call the weapons something different but use the same damage equations. Other times we may change up the mechanics a little bit. Maybe the damage goes up when the skeleton uses a greatsword. We can also give humanoid creatures better armor, using the new AC the armor holds. An ogre or troll in splint armor now has an AC of 17.

Elemental Flavor

We can give nearly any monster an elemental flavor by giving it bonus damage and damage resistance based on that element. Need a fire scorpion? Add 3 (1d6) fire damage and resistance to fire. Want an acidic hook horror? Give it 3 (1d6) acid damage and resistance to acid. You can always increase the extra damage for higher challenge monsters as well, say 3(1d6) per every four challenge ratings. Looking to add some variety to your monsters? Here's a random 1d10 list of elemental monster variants you can roll on:

  1. Fire
  2. Cold
  3. Acid
  4. Lightning
  5. Poison
  6. Necrotic
  7. Radiant
  8. Thunder
  9. Psychic
  10. Force

There, you just got 10x the number of monsters in the monster manual.

Easy "Dire" Monsters

Older versions of D&D included "dire" monsters; huge, powerful, and primeval versions of typical monsters.

Here are the steps to create a "dire" version of monster:

This will make it roughly twice the challenge rating, recognizing that CR is a mostly worthless tool for such tweaks.

Stealing Features from Other Monsters

When tweaking monsters, we can also steal a trait or two from another monster. This might be a creature type, such as undead for skeletons, or a monstrous feature such as a zombie's undead fortitude.

These two examples alone are very powerful, letting you create zombie fire giants or skeletal wyverns.

The Dungeon Master's Guide offers modifiers for NPC stat blocks to customize the NPCs listed in the Monster Manual including both the "Skeleton" and "Zombie" templates; powerful templates to create a huge range of undead.

Mashing Up Monsters

Going beyond stealing a feature or two, we can mash together two whole stat blocks to create something unique. The vampire spawn stat block, for example, works well as an overlay for just about any other monster to make it a unique vampiric version of the base monster.

When mashing two monsters together like this, choose the most complicated monster as your base monster and the least complicated as the template. A stone giant lich, for example, works best when the lich is the base stat block modified by aspects of the stone giant stat block.

You can read more in my article on mashing up monsters.

Monster Difficulty Dials

Monsters have some built-in flexibility we can use to tune the pacing of our battles. The listed hit points, for example, represent only the average of a monster's hit dice. We can turn this dial up and down, increasing or decreasing the monster's hit points. We can even do so during a battle if we want to change the pacing of the fight. If a battle is dragging on, turn that dial all the way down and have the monster die on the next hit. If things are going too easy in a boss fight, turn the dial up.

We can do the same thing with the number of attacks and the damage of those attacks as well. A fourth dial changes the number of monsters in a fight. Some might run away while other times reinforcements turn up.

Here's a summary of the four dials:

A Bottomless Well of Monsters

With these few techniques, you can take the monsters in the Monster Manual and turn them into any twisted beast you want. That single book is now a window into a bottomless void filled with the greatest horrors of your imagination. Enjoy!

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This work includes material taken from by Michael E. Shea available under a Creative Commons Attribution-NonCommercial 4.0 International license.

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