"Wait, that didn't work right" - the Dysfunctional Rules Collection

[Gnomish Wanderer]

The Battle of, say, Waterloo had 180,000 combatants, and yet 450 soldiers did not inexplicably drop their muskets every six seconds (unless, of course, they were dead). Having such a high chance of gruesome screwups is preposterous.

I could argue you're simplifying the mechanic, because it includes everything from dropping their weapon to hitting the wrong target to failing to reload to tripping to any number of dumb mistakes. I actually find 450 still reasonable out of 180,000 people. People are inherently fallible.

This means that if a level 20 fighter spent one hour sparring against a practice dummy, he would stab himself (or drop his sword) six times.

I think your math is off. I only see any level fighter having 1.5 critical mistakes in an hour. Which, again, makes sense to me.

Regardless, I agree any crit. fail mechanic would be hard-pressed to be realistic, but it makes one damn good storytelling and drama element.