Erosion is a geological card game, that lasts but a half hour. Struggle to keep your mountain uplifted while weathering and eroding the mountains of other players. The deck is divided into sedimentary, igneous, and metamorphic rocks. The winner is the player who has the highest mountain, and accumulates the most material in his delta, with a bonus for fossils.

The basic rules of Erosion introduce the four player actions: Weathering, Hillsloping, Fluvial (River), and Draw Cards. The advanced rules demonstrate how mountain-building and erosion control Earth's climate and atmosphere.