In Ach Du Lieber Biber, beavers are surfing the waves of the icy river towards the waterfall, but while they do so, they have to beware of the floating junk and other surfers. The player who lets the fewest beavers tip over the waterfall wins the game. In more detail, the players place the water cylinders on the river and randomly organize the surfing beavers and junk markers on top of them. They take turns rolling a "surfing die" to determine whether they have to progress the water level, with the aid of a wooden lodge across the river, towards the edge of the waterfall.