Norfleet said:Well, if I were running a game, I'd declare a fumble anytime a character's to-hit was negative. Making it happen on a 1 seems ludicrous, as a character would then fumble and make a fool of himself once every 20 swings....which is WAAAY too high for somebody who has any idea what he's doing. On the other hand, if you can get a negative attack roll result, you clearly don't know what you're doing, and are at risk for impaling yourself.
My rule is that when you roll a 1 in melee, you provoke an attack of opportunity. QUick, easy, and gets the idea across. Also makes combat more dramatic. For ranged, you might hit someone if they're in your line of fire. DM's call in that case.