Situational Crit Fails

Critical hits are an integral part of D&D. Everyone loves rolling a 20. Cries of "twenty!" can be heard around the table, players cheer, and overall it's just a great adrenaline hit. On the other hand, crit fails just aren't fun. Rolling a 1 can be an auto-miss, but having your character drop a weapon or rolling on a crit fumble table just isn't a good time for players, which is why so many tables (my own included) have just done away with critical failures. But what if there were a way to incorporate critical failure in a way that didn't make players feel cheated? I've got an idea, which I have yet to implement, and I'd like to share it with you.

Item-Specific Critical Failure

You can introduce a special magic item to your party which has effects that come into play only on a roll of 1. Everyone loves vicious weapons, which do an extra 7 damage on a critical hit. But what about adding minor drawbacks to a weapon which only take effect on a 1? It's one way to make that magic item you've been hesitant to give the party slightly less good. Think of a vampiric sword which steals hit points from enemies. Maybe on a crit fail, it steals 1d8 hit points from the player wielding it. Or a wand of acid arrow which misfires on a roll of 1, leaking acid from the wand's tip - the wizard takes 1d4 acid damage and has to save or drop it. 

This approach is difficult because so many items such as armor, fireball wands, and helmets don't require rolls. But baking the crit fail into a magic item from the outset can help to set expectations, ensuring that your players don't feel that the rule is unfair. And if designed creatively, it can add a lot of character to a weapon.

Flavoring Crit Fails on Ability Checks

One of the simplest ways to actually make use of those infrequent 1's a player may roll is to rule their effects on skill checks on the fly, without even making any official crit fail policy at the table. If your player rolled a 1 on the climb check, say that the character fell and took 1d6 damage. If the bard rolled a 1 on his persuasion check, she's gone and offended that merchant she was trying to bargain with. A crit fail on a perception check might give a false positive, and have a player think there's a trap where one doesn't exist. Of course, this only works if the DM is rolling those perception checks behind the screen.

In any event, this is a minor thing, and most people wouldn't even consider a 1 on a skill check as a proper critical failure.

Wild Magic for Everybody

Wild mages can be a fun class to play, but how strange is it that normal magic-users never have their own magic go awry in any way? 

Rolling a 1 on a concentration check seems like it would be an incredibly infrequent thing, especially given that at my own table, we forget to roll concentration checks most of the time. But I think it's a fantastic idea that if an arcane caster gets hit, and seriously flubs his concentration, wild magic happens. No spell is lost that otherwise wouldn't be, and given how generous most wild magic tables are to the players, it might actually help.

If you're looking for wild magic more interesting that what's in the PHB, I recommend my own wild magic surge table.

Crit Fails on Saving Throws

Saying that your players take extra damage if they roll a 1 on a save vs a fireball is just no fun. I'm not recommending that you go with that. But as a DM, you can improvise. Rather than extra damage, perhaps the character's pants have caught on fire. Remember that greasy meat you ate at the tavern for lunch? You kept wiping your hands on your pants, and all that grease was pretty flammable. Perhaps the character rolled a 1 on a save against a shatter spell? His ears are ringing, and he's got disadvantage on perception checks for a few hours. Or perhaps the wizard had to save to avoid falling into a pit trap and rolled a 1. His robe got hung up on the trap's hinge and he's now hanging from the side of the pit trap, restrained. There's one that the players will remember. Now he needs an athletics check to shrug out of the robe, but then he'd fall into the pit naked. Tough break. Remember - we're all sitting around the table to have fun, and no-pants, ringing ears, or hung-on-the-wall aren't numeric game penalties - they're just fun stories.

Choose Your Own Fumble

A great way to handle things when a player rolls a 1 on an attack is to ask the player what happened. "Okay, Ragnar rolled a 1. Tell me what happened there. Describe for me how he epically failed that attack." Encourage your player to be creative, funny, and to describe something interesting. If it's good enough, give that player inspiration. Maybe he'll describe smacking himself in the head with the hilt of a weapon, slipping on the blood from that kobold he just killed, or his helmet slipping over his eyes. This involves the player in the storytelling, and that's always a good thing.