I've kept bouncing around my homebrewed d12 system in my head, and it has now taken on characteristics of FATE and Feng Shui. I'm still a little unsure of how exactly the probabilities will play, but we'll see.
So here's how it's laid out.
Roll 2d12 when it is deemed necessary by the group (explained below).
Subtract lowest from highest, resulting in numbers from 0 to 11. 0 (a double) explained further below.
Add up to +5 with modifiers. (+6 with plot point. See below).
Then the modifiers come from five aspects that describe your character, then three skills/achievements/training/merit badges, and then possibly equipment depending. A magic sword that does extra damage against Orcs would likely get a +1 against an Orc.
So Let's say I'm a wizard and want to cast a simple magic missile spell. I roll my 2d12, and the roll come up as a 6. I can add aspects, training and equipment, but only to a maximum of +5.
I have an aspect 'spellslinger', training in 'magical casting' and 'magic missile', and I'm carrying a staff that helps me channel my magic. That's +4, so overall I get a 10. If that 10 beats the targets dodge/armour, it takes damage (I haven't quite worked out the damage track yet).
If I'd rolled any kind of double, then something different happens. I instead earn the group a plot point, which I could either spend immediately to make some riotous example of the spell going amazingly, or keep and allow the spell to fail somehow. The plot points are communal, so anyone could use them. They let the players make narrative choices or give them a further +1 on rolls (similar to FATE).
How does this sound to people? So far, my ideas for testing it involve the Lookouts (for those merit badges as skills), Psychopomp and maybe some sort of high science fantasy setting in the cosmos.