Originally invented for a backpacking trip into the Grand Canyon, where the creators wanted to take multiple games with them. To save weight and space they put them all into one! Great for travel or at home play, alone or with friends! We believe that house rules are official rules. By that, we mean you pick how you play the Flex Deck. Mix classic systems of fun with double-nine dominoes, word games and traditional card indices, all in one. Fun for all ages!