Epiphany is a dice-less roleplaying game from Greg Porter and BTRC. Note that it does not use GM fiat, unlike many dice-less roleplaying games.
In Epiphany, a character's traits (such as attributes and skills) are not measured by numeric or a word scale, but by whether the character has that trait at all. Anything that is not so easy that anyone can do it is a Challenge. Any trait that helps a character in a Challenge is an Advantage and any trait that hinders a character is a Disadvantage. A character always has a "free" base advantage. Some Challenges succeed simply if a character has more Advantages than a certain number (say, 3 Perception related Advantages to notice the door hidden in the ornate paneling of the wall). Challenges between a character and an opposing force (say, another character) are resolved by each side deciding how many of their Advantages to apply to Offense (indicated by the number of fingers extended on the right hand) and how many to Defense (indicated by the number of fingers extended on the left hand); and then both sides show their hands simultaneously. A Simple Challenge is done once, with whoever is more successful being the winner. In a Complex Challenge the side whose Defense was less than the other side's Offense loses a number of Advantages equal to the difference between the two for the rest of the Challenge, which continues as a series of Simple Challenges until one side is out of Advantages or gives up. If there is a stalemate, clever players can think up something that would get them another advantage, or they can start another Challenge of a different sort while the first Challenge continues in the background.
The (minimalist) setting described in the Epiphany is a fantasy setting with some interesting twists, but I think that the system could easily be used as a generic system in any setting.