If rock-paper-scissor is too simple for you, then you can try David Lovelace's RPS-15, with 1.3 trillion permutation and 105 possible outcomes. Still too simple, try RPS-25 with 15.5 octillion permutations and 300 outcomes. Link
BIG NEATOSHOP SALE: GET UP TO 20% OFF T-SHIRTS (ENDS 3/8/15)
Save big on Funny T-shirts, Science T-shirts, Sci-fi T-shirts, and more!