On Critical Fumbles

The internet hates critical fumbles. Home games tends to love them.

There are various rules of thumb for telling you that your critical fumble rule sucks, such as: if ten trained warriors spar with inanimate dummies, if any of them are dead at the end of an hour, your critical fumble rule sucks.

The "correct" way to play is without critical fumbles at all. A natural 1 is an automatic miss, that's all. The problem with this is that it is of course boring. Spice up your life a little! That's what critical fumbles are for.

The worst way to play is that a natural 1 is an automatic critical fumble. Nobody is going to hit an ally or whatever 1/20th of attacks they make, especially if they're highly trained. And if you're a high-level fighter, you're making 3 or 4 or more attacks a round, so you're going to fumble every few rounds.

A better way to play is that a natural 1 is a threat for a critical fumble. It works just like critical hit threats: you roll again at the same bonus, and if the confirmation would miss your target's AC, then you fumble. This is better because it makes it difficult to fumble against softer targets and easier to fumble against targets that are actively trying to foul you up, and it partially ameliorates the "high level warriors fumble more than low level ones" problem in that a high attack bonus makes you fumble less and a more skilled opponent makes you fumble more. Still, a level 16+ fighter is rolling at -15 on his fourth attack. So it's not perfect.

A much better way to play is that a total roll of 0 or less is an automatic critical fumble. This way, if you have any positive modifier to your attack -- or even no modifier at all -- you will never fumble. Skilled warriors never fumble, unless they're stacking massive penalties. You only fumble if you suck at life -- which some low-level PCs and monsters do (especially low-level monsters with secondary natural attacks).

Even then, you should have some variety in critical fumbles. A fumble is always just a provocation for attacks of opportunity is fine, but a little dull. I recommend the Paizo critical fumble deck.

While you're at it, you might as well throw in the critical hit deck, too -- but only for PCs and major (e.g., named) NPCs, because it makes critical hits a bit more lethal.