I strongly recommend that you urge your DM to ditch fumble and critical tables altogether. It sounds like this will be difficult to do, but you’ll find the game much improved – and, I think, so will he. This is because...
Critical and fumble tables have myriad problems
The Dungeon Master’s Guid...
does this constitute an appropriate "challenge" to the question? (it's barely even that since it has recommendations for even using the damn tables)
but mxyzplk has felt it appropriate to knee-jerk downvote and comment dismissively, so I want to make sure I haven't messed something up
@JoshuaAslanSmith tell me about it
@JohnP this argument is mathematically fallacious; see my answer
they are not the same
@JohnP do you do that on 5% of the things you ever attempt to do in your life?
because based on this guy's table, you would
mind you, do you think you would still do that on 5% of everything you did, if you were a legendary hero, veteran of a hundred dungeons and thousands of fights to the death with vicious monsters?
would you, in fact, expect to be more likely to "eat a foot" after gaining all that experience?
because that's what's going on here, and it's more-or-less what happens with every fumble table ever written
for d20, anyway
the system is just inherently incompatible with them
@DavidWilkins also, even if the DM exclusively uses monsters with lots of attacks, and none of the party does, the typical game has what, a couple dozen “unimportant” foes for every enemy who really, truly counts? the DM definitely should not be using monsters that get orders of magnitude more attacks, at any rate
so even if your argument is true (doubt it's true on average but it's conceivable for a particular table), it's not true "enough" to counteract the math
@KRyan, it's a matter of magnitude. Your answer is fine and challenges the frame - down through the end of your FATE section. Then adding another 2 linear pages of "HERE'S WHY FUMBLES ARE AWFUL" detracts from it.
You make your point, but then you efefctively decide to hog up a couple more pages of space with the tangent. It would be appropriate if the question were about that, but it's not. So you should show moderation in how much you present in that context.
@mxyzplk I downvoted every answer that suggested that using a critical or fumble table as-is was anything but a bad idea; can't speak for anyone else, but I really stand by my statement that they are always bad and thus those answers are all bad suggestions
@KRyan I am a 4th degree black belt. Multiple state championships, been ranked top 10 world in our system and fought for a World title. Been in martial arts since 1986. Two weeks ago in our tournament I slipped landing a technique and got a nice whip kick returned off the side of my head. Yes, it will happen.
@KRyan No. But that's why I think you should roll to confirm the crit, if you roll 1, 1, yeah something should happen. I disagree with the table that yutz has put together though. At most you might be caught flatfooted or provoke an AoO
@KRyan - I also don't land spectacular techniques 5% of the time either. I agree it's a skewed representation, but you can't support the "YAHOO!" 5% of the time as being perfectly acceptable and at the same time decry the "Oh, @#$" 5% of the time either.
Roll to confirm hit, roll to confirm crit, and make the fumble realistic. (Such as the sword twists in your grip, and you lose initiative to the end of the next round while you readjust).
I don't agree with fumbles where the sword goes flying, or you do the Daffy Duck "Ho ha hee dodge thrust parry WHACK!!" thing.
I say, if you want fumbles, roleplay them. Take real life as an example where professionals make mistakes. "Roll a 1? Ok you are now addicted to shire weed. or: Word gets out that you hit your wife once in the tavern. "
@DavidWilkins - I agree, roleplay it. You attack with a sword and roll a 1. Ok, now roll again. Anything but a 1, you just miss. Another 1, and give a consequence, but not one that would result in party wipe or absolute chaos.
the way we play at home (and I confess to hating it, but everyone else seems to enjoy it), is that if you roll a 1, we roll d%, 10% or lower and something bad happens, 90% or higher and you get a reroll
@JohnP I'd agree you can, honestly. Critical hits don't punish the players for existing and don't kick characters already hurt by the math while they're down. The goal isn't simulationism in the first place anyway.
@waxeagle 4e has better math in general. 3.P has a lot of attacks that can natively just finish off yourself or a party member, especially for people who are playing attrition games (somehow) and thus entering fights pre-wounded.
@JohnP the difference is that critical hits are something that you do, on your turn. Enough bad things will happen to you on enemies' turns, and losing your opportunity to respond (e.g. auto-miss) is already devastating; giving them more "for free" (e.g. not even on their turn, not using any action of theirs) just doesn't work well within the system
@KRyan GH,BM came out as an article in one of the earliest Dragons and was used by my 2e DM (Daaaad) to add flavor to critical hits and fumbles, keeping in mind that a fumble back in 2e already stopped your entire attack routine and ended your turn.
It had stuff like "drop weapon" or "trip", but then it had stuff like "critical hit, self"
Anyway, the horrible, HORRRRRIBLE chart provided one of our most hilarious scenes. Gundam the orc samurai charging zombies to save his master (who just slipped and went unconscious for 4 rounds while trying to shoot a crossbow in melee, with the hope of hitting the party rogue/ranger/barbarian/wizard elf weretiger who just hit him with an arrow because of cover), and dislocating his arm becoming unable to hold his katana, that he never learned to wield one-handed because the samurai class gave him bonuses when he used it in two hands.