The use of games as teaching devices is receiving attention from an increasing number of educators. Data from tests conducted with one such educational game-WFF ’N PROOF strongly indicate that this and similar games are useful, not only in teaching a particular subject (in this case symbolic logic), but also in increasing the general problem-solving ability of the student. WFF ’N PROOF is actually not one game but a series of 21 games of increasing difficulty. The first games in the series are quite simple and can be enjoyed by first graders. The final games are challenging and stimulating even for a university teacher of logic.
Allen, Layman E. "The Virtues of Nonsimulation Games." R. Allen and J. Ross, co-authors. Simulation & Gaming 1, no. 3 (1970): 319-26.