Noodling/Dice Size RPG

Dice Size RPG

In a dream recently I invented this rpg mechanic. It's not bad so here it is: when you do a skill check, you roll a die. The size of the die depends on the skill and the circumstance - I think in the dream fighters usually rolled a d8 for a sword attack and spellcasters rolled a d12 for a spell. If the skill check is riskier (I think in the dream the example was attacking a large monster), then you bump a die size. Results are like this:

 1: Success + extra
 2-3: Success
 4-6: Partial success
 7-10: Failure but with some redeeming aspects
 11-15: Failure
 16+: Everything is terrible

So like a sniper shooting at an unsuspecting target rolls a d4, so they get what they're trying for 75% of the time. A fighter in combat usually gets a good hit in but sometimes has stuff go bad, especially if they're up against an ogre or something. A wizard casting spells is always taking some risk and if they have to cast in a rush then things are likely to go bad but they might get lucky.