In this "alternative universe," prime numbers are formed instead of words, and numbered tiles: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 are played instead of lettered tiles: A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W, X, Y, Z.