There's a neat little system called "Otherkind Dice" that's described on this page:http://www.lumpley.com/archive/148.html
Basically the idea is this:
Whenever someone is trying to do something which isn't an automatic success, the GM can call for a roll.
The player has to say three things:
- What they're trying to accomplish. ("Get through the trap-filled corridor", "Knock out Doctor Z", "Rescue the kitten from the burning building")
- Plus, two things that the character is risking by doing this. ("I get skewered by traps", "I lose my favorite sword", "Doctor Z imprisons me", "My secret identity is revealed")
The player then rolls 3 dice (normal six-sided dice). High numbers are good, low numbers are bad. They then have to assign these dice to the three things, which determines whether or not they succeed, and what it costs them.
Captain Fantastic sees that his girlfriend, Penny Petticoat, is being held in one of Doctor Z's deathtraps.
The player says:
1) I am trying to get Penny out of the deathtrap by melting the steel bars with my heat vision
2) But... Doctor Z's goons might rough me up pretty badly,
3) And... Doctor Z might use this as a distraction to escape in his Ultrabot.
They roll... 1, 3, 6. So they decide that:
6 -- I rescue Penny, melting the steel easily and catching her in midair. I look like a champ.
But 3 -- I have to fight a lot of goons first, and I take a couple of shots. I'm hurt. (3 is low, but not terrible.)
And 1 -- Doctor Z makes a clean getaway. I can't even tell which direction he went. (1 is very bad.)
Or they assign the numbers differently, for a different result, and then write the story in that direction instead.
Note that there are no stats for characters in this system -- everybody is the same from that perspective. Your stats and abilities come into it when you write the different possibilities. If someone is described in the character writeup as being super-strong, then it's okay to say that your goal is to bend the steel bars and rescue your girlfriend. But if not, then the GM can/should step in and say "Hmmm. That doesn't seem to fit your character. Can you think of a different way to try that?"
I've tried this system in live games and it's worked well. I'm a little hesitant to recommend it for a forum game, as it works best with a little bit of back-and-forth discussion to make sure everyone's on the same wavelength, and that could slow things up. But figured I'd throw it out there in case it's of use to anyone.