Funky Wonky Monkey
So I had this dream about a new system a friend was trying out, and we were playing along with great characters (mine was an ex-Jedi who abandoned the Council because he had figured that love was more important) and enough of the system remained when I woke up to suggest it as a little fun add-on to your diced system of choice.
Three dice (d6) are added: one is a black one (the "funky"), another is red (the "wonky") and another is unusual in some fashion (the "monkey.") These dice can be rolled in any order, and in any combination of two WITH the regular dice roll, BUT they have to all be used once before you can roll one again... so you could roll a funky, a wonky & monkey, and then a funky & wonky, but no duplications until all three have been added.
The "funky" die is an add-on that modifies the result into something unusual but positive. So even if it's a critically bad roll, there's a spin to it that makes it neat. ("Oh man...you just blew up a BUS. Full of CHILDREN and NUNS. Dude! It's like fireworks!")
The "wonky" die is an add-on that modifies the result into something not quite working the way it was expected. Not necessarily negative, and definitely subject to entropy. ("Oh man...you just blew up a BUS. Full of CHILDREN and NUNS. Dude! Um. It's still going. We oughta...um...run.")
The "monkey" die is an add-on that modifies the result into Something Completely Different. Not negative or positive, but something that changes things, maybe even the current scenario. ("Oh man...you just blew up a BUS. Full of orc scum dressed as CHILDREN and NUNS.")