by Mike Shea on 22 December 2014
The flat-math design of D&D 5th Edition simplifies monster customization to change their behavior or increase their power. Like reskinning, attribute modification is simple enough to be done at the table. You don't need to write anything down, all you need to do is know how an increased stat will affect a creature.
For this article, we'll be looking at monsters from the D&D 5e DM Basic Rules. If you don't have a copy, go download it now so you can follow along.
Let's look at some examples.
Let's start with the basic gnoll on page 30 of the basic rules. As listed the gnoll has a strength of 14 (+2). What if we want to make a champion gnoll among his tribe? Maybe he's personally touched by Yeenoghu. Instead of a strength of 14, this champion of Yeenoghu has a strength of 19 (ogre strength). How does that affect his performance in combat? If his strength started at 14 (+2) and we modified it to 19 (+4) we add +2 to his attacks and +2 to his damage.
You can tweak monster attributes like this for any monster you choose. In general, if you want to see an attribute have an affect at the table, modify the primary attribute of the monster. For example, let's say you want a tougher named mage. With a base intelligence of 17, you might boost her intelligence to 20 instead of 17, giving her +2 to DCs and spell attacks. As her primary stat, intelligence will have a big effect when tweaked.
Returning to our Yeenoghu-touched gnoll, he's likely to be tougher than a normal gnoll so we'll increase his constitution on top of his strength. A baseline gnoll has a con of 11. What if we give him a constitution of 16 and give him +3 hit points for every hit die (15 extra hit points). Now the gnoll has HP of 37 instead of 22. If you want something a bit simpler, just double the hit points. The difference won't matter too much during the game.
Now, with strength like that, this particular Yeenoghu-touched Gnoll might want a better weapon so let's take away his shield (-2 AC) and give him a greataxe (1d12 instead of 1d6). Now his attack is +6 for 1d12+4 damage on a hit. Powerful!
Note that instead of just tweaking the math directly, we actually have a story-based reason for the changes in mechanics. Our powerful gnoll dumped his crappy shield and picked up a great axe that most normal gnolls couldn't lift. This gives us flavor reinforced by mechanics instead of mechanics strictly for the sake of gameplay.
With all of these tweaks our new gnoll is likely to need a boost in its challenge rating as well. For the changes above, it's probably a CR 1 creature instead of the CR 1/2 creature we've seen before. It's roughly double what a normal gnoll is.
If you're only increasing or changing one stat, you can probably get away with it and not change the CR. If the creature poses a much greater threat by increasing more than one stat, you might want to increase its CR. If it's roughly twice as powerful, like our gnoll, double the CR.
In the beginning of this article we said that you could likely alter a monster and not have to write anything down. Even with the changes above we can likely keep it in our head but with enough of these changes we might as well jot it down on a 3x5 card. For our Yeenoghu-touched Gnoll we only have to write down the following:
Yeenoghu-touched Gnoll: AC 13, 37 hp, +6 to hit, 1d12+4 dam
This is just one way we can tweak monsters to fit the theme of our adventure and keep our players on their toes. Tweaking attributes and changing out equipment is just the beginning. Next time you want a monster to stand out from the rest, play with its attributes and describe the story of the results!