A couple of years ago, I had an idea for my then-upcoming campaign: don’t use any stock monsters — and by “monsters,” I mean “adversaries” in general. This sounded like fun, and it was, but I encountered a few stumbling blocks along the way.

Let’s take a peek at two reasons why you might want to use custom critters, five ways to do just that, and a bit of advice about what works best.

What’s a stock monster? Stock = as-is, straight from the book. Monster = anything the party is likely to fight (a dragon, a platoon of space marines, a trio of MIBs, etc.). There’s nothing wrong with stock monsters, but they also don’t hold many surprises for experienced gamers (and no surprises at all for the folks who can memorize rulebooks!).

There are two big reasons why avoiding stock monsters is neat: as a GM, it’s fun to take a break from “the usual,” and because your players won’t know what to expect. The goal is to have fun by restoring some of the sense of wonder that comes from encountering something potentially deadly and having no idea what it does. This is obviously less important in games where “PCs vs. environment” isn’t the main source of conflict (like Wraith: The Oblivion, or — even further down that spectrum — Primetime Adventures), and more useful in games like D&D.

With that in mind, here are 3 ways to mod your monsters:

  • “Palette swaps” (to borrow a term from video gaming), where you use the monster’s stats as-is but change its appearance.
  • Templates, which add a layer of changes to the monster’s stats.
  • Custom abilities (“These fire elementals can shoot flaming darts”).

…plus 2 methods that don’t involve modding them at all:

  • Make up your own foes.
  • Use monsters from obscure sources (which, while technically still “stock,” accomplishes nearly the same thing).

“No stock monsters” was one of the things I wrote in my notes while planning for my Selgaunt campaign, and I tried to implement that rule throughout the game. It didn’t go so well, for two reasons: at low levels in D&D, the monsters are so weak that you don’t have much room to fiddle with them; and second, because mechanical changes can be pretty time-consuming.

Back to the problems, then — let’s start with low level foes. After poring over my books looking for templates that could be applied to things like kobolds — and finding very few that met my needs — I gave up and switched to palette swaps and obscure monsters. By and large, that worked pretty well — the PCs fought some things that were memorable not because of their mechanics, but because the group didn’t know what they were.

At later levels, I found that prep time became the larger issue: even though I could use things like templates and custom abilities more easily, picking them took too long. More recently, I used a template on a couple of monsters in my Airship Privateers campaign — but didn’t have time to modify their stats before the session. The result? I had two books open at the table, and during combat I forgot one of the most important things about the monsters.

Based on my experience, the two easiest ways to avoid stock monsters are to pull from obscure sources or use palette swaps on familiar foes. Neither approach requires much in the way of prep time, and done right they can be pretty powerful tools.

Customizing abilities can also be fairly straightforward: just take out one element and replace it with another, and try to keep the monster’s overall power level about the same. Make sure you pick something that’s likely to come up during play, though — because while deciding that these orcs are immune to poison is fine, it’s a wasted effort if none of the PCs are going to use poison against them.

If you go the template route, or make substantial mechanical changes, make sure you do it during prep. In the case of D&D, many books with templates in them (like Advanced Bestiary, from Green Ronin) also include one templated monster for each listing — a nice timesaver, if the sample creatures sound like fun to use.

What are your experiences with avoiding — or not avoiding — stock monsters? Do you have any tricks or suggestions about the 5 methods listed here?