Trifix

This game was handed out to all participants of the mathematical kangaroo competition 2011 in Germany from 5th grade on. The rules are identical to the well known card game SET but uses different cards.
The game consists of 81 round (!) cards showing one of 3 different shapes (triangle, tetragon, pentagon), quantities (1, 2 or 3), colors (blue red and orange) and fillings (full, empty or structure). Each possible combination is represented on one card. Cards will be laid out in a 3x4 grid. Simultaneously the players are looking for a 'trifix', a set of 3 cards where in each of the four categories (shape, quantity, color and filling) all 3 cards are all alike or all different. If one trifix is found the player gets this and the cards are replaced from the deck. Then play continues. Winner is who has found the most trifix at the end.