WFF 'N PROOF is a game of modern logic, developed to teach principles of logic. WFF 'N PROOF was developed by Layman Allen a former professor of Yale Law School and the University of Michigan.
In the game, students must be able to recognize a "well-formed formula" (WFF) and use seven different rules of logic to manipulate those WFFs into a proof. Games are played in groups of two or three. The first player rolls the cubes and sets a WFF as a Goal. The goal is the conclusion of a proof. Each student then tries to construct a proof that ends with the goal. The Solution to the goal is the Premises which they started their proof with, and the Rules they used to get to the Goal.
Players take turns moving to the Essentials, Permitted Premises, or Permitted Rules sections of the mat. Any cube moved to Essentials must be used in any Solution, and must be an essential part of that solution; any cube in Permitted Premises may be used as part of a premise; any cube in Permitted Rules may be used as part of a Rule. Thus the players themselves shape the Solution, forcing one another to create new Solutions in response to moves.
At any point a player may challenge the last mover, if they feel the last mover has made a mistake. There are three types of Challenges. A-Flub means that the Challenger can make a Solution using the cubes in Required and Permitted and one more cube from Resources. P-Flub, or Challenge Impossible means the player believes the Mover cannot make a Solution using the cubes in Required, Permitted, and Resources. C-A- Flub means that the Challenger believes that the Mover, or some previous mover, missed an A-Flub. After a challenge, at least one player must show a correct Solution on paper.
The scoring goes like this:
The player who wins the challenge scores 10 points.
The loser of the challenge scores 6.
If there is a third player, he must side with or against the Challenger and scores points depending upon that decision.
A game may also end in a Forceout.