So nice, I had to steal from this and expand on it.

Skills can be checked for success by rolling your ability score or under on a d6 scale. You can combine two ability scores if it calls for it and roll d12. The difficulty of the check is solely at the discretion of the GM.

Any percentage-type abilities can be calculated in the way above. for each 5% in an ability (rounded down) counts as a +1 point bonus to the ability score rolled against. So a 3^rd level Elf Thief attempting to pick pockets (40% + 5% Elf bonus) with a 15 Dexterity would need to roll a 24 or below with Xd6 (X being the number of die rolled based on difficulty). They have 45%, so there is a +9 to the ability.