It's not to baby the players, and it wouldn't work with every game system (such as AGON which relies on competitive rolls) -- and I am thinking in a strictly D&D gaming environment. But has anyone used a house rule that every roll the players make is a success to a degree? They always succeed on their stated goal -- always hit the enemy, always steal the bag of gold from the baron's desk, et cetera -- but how well they roll determines how well they do.
Attacking: Rolling a lower number may result in less damage, stumbling afterwards or spoiling their defense in some way OR a higher number would be more damage or some other negative effect on the enemy. This also puts fighters on terms with casters, at least in terms of being able to hitting their opponent.
Theft: Yes, you stole the bag of gold from the desk, but since you rolled a 1 there are obvious fingerprints all over the desk. Or a 20 would be a perfect theft -- now, sneak out of the castle.
Numbers in the middle range would just be normal successes.
To me, this eliminates two related problems: Arbitrary, binary success (either you are or you aren't, and the DC is set by saying "You must hit this number") AND bad luck dice night (I don't need to explain this). I've found that these two often combine and spoil a night for one or more players. If they always succeed at hitting or stealing or dancing or whatever but to varying degrees I'd be sacrificing some challenge for more fun.
What say you?