The game has 4 sets of 20 thick wooden tiles in 4 colors, which are numbered from 1-20. The 4x5 fields of the board also show the numbers 1-20.
Object of the game is to score the most points, but these points are given at the end of the game only! The game ends when all 80 tiles are placed on the board, but only the top tiles are valued; adjacent tiles of the same color give bonus points.
To reduce the influence of luck, the hand of 10 tiles is not filled randomly, but can be taken from 10 open tiles. Anyway, it's a game where you need a good memory, because you should remember which tiles have been played already and thus can't help you getting some bonus points.
This game is very easy to learn and play, but it's not so easy to find the best strategy.