Abstract two-players-game on a leather-plan (which you can tighten to a little bag) and with semi-precious stones as counters.
Both players have 13 counters, 8 in one and 5 in another color. The plan has 13 fields. During the game, the players "color" the plan with their stones, at the end every field has one of four possibilities of stone-combination.
To win, you want to create less equal color-combinations in adjacent fields than your opponent.