Errr.... it uses Feng Shui. It has its own, simple, flexible rules.
2d6, one is low, one is high. Roll 'em, subtract the Low dice from the High dice, and add your skill. Reroll all sizes. Before rerolling sixes, that'll give you a range of -5 to +5, in addition to your skill. It uses target numbers, like DCs or ACs, and the difference between the DC and your roll affects how much damage you do. It's fun, fast, and not too tough.
Example: my martial arts skill is 11. I want to grab a named bad guy (as opposed to a faceless mook) and flip him back over the wall of an open air fish stall, and hit him with a big fish while he's sliding on the slippery ice and merchandise.
I roll my two d6, different colors. My Low die is a 3. My High die is a 6. Whoo hoo! I reroll it and get a 4. 4+6-3=7; 7+my martial arts skill of 11 = 18. Doc Midnight knows that this guy's dodge skill was 14, so I'll do 4 points of damage in addition to my normal martial arts damage. If he's really buff, that might not hurt him much; if he's fragile, he might take some decent damage. But no matter what, he'll look dumb, and in Feng Shui doing something embarrassing is ABSOLUTELY worse than getting hurt!