10 Tips to Being a Better Dungeon Master – A Dungeons and Dragons Guide

[Lanefan]

This is certainly a possible solution to help balance different mechanical subsystems within a game (martial damage vs magical effects). I still don't consider a lack of critical failure a flaw though - its a mechanism to balance a game and not just crit hits need to be balanced with crit failures.

If you roll to place AoE it lowers the effectiveness - it is now harder to get optimal placement. If you also allow critical failure wen rolling to place AoE it lowers the effectiveness even further - you now could hit your own party. This brings magic down in effectiveness to make sure damage can compete as a viable option.

Exactly!

Alternatively you could add criticals to damage and increase its effectiveness to compete with magic.

Also done, and both of these ideas come from back when I started DMing.

I find that critical failure cannot be implemented without making the game either much gimmer or much more comical (unless you brush over the failure so casually that you might as well not have bothered). Critical hits less so. Though they can still have their own comedy moments. I had a game where a possessed baker bludgeoned a PC unconscious and to the brink of death with a loaf of bread. The PC was only saved when another PC doused the baker with water, making the bread soggy and less effective. All of this from a critical hit.

Neither of grim nor comical bother me in the least.

In my game, if someone rolls a fumble (which needs a confirm roll of 1/d6 after the 1/d20) there's a table that gets rolled on - the most common melee effects are minor e.g. drop weapon (or, less commonly, shield), or hurt self or ally for d4 damage, or slip and give foe a free attack; stuff like that. But there's also a lesser chance of doing something more spectatular e.g. throw weapon in a random direction, or critically injure self or ally, or destroy weapon (which, if it's a magic weapon, can sometimes generate follow-on wild-magic effects as all that bound magic is released at once) - that sort of thing. Missile fumbles use a different chart but with the same idea of most fumbles being relatively minor (by far the most common are broken bowstring, and glancing blow to ally if one is in the way to be hit), and spell fumbles are almost case by case as the possible effects so greatly depend on the specific spell being cast.