In Yak, the village elder has given you (and others) the task of constructing a great stone tower to guide the merchants and their yaks in the Himalayas. Each turn, a yak pulls its cart into your village. Will you find stones for your tower, or food for your reserves? Or will you need to visit the market to find what you need?
Over the course of the game, each player builds their own stone tower by acquiring stones from visiting merchants. You start the game with one good of each type (meat, milk, bread) and three cards in hand: build, restock, and market. Three or four carts being pulled by yaks start on the game board, with each player having one cart in front of them and each cart containing three stones and some food. Each cart has a restriction on it, e.g., "no bread" because its yak is gluten intolerant.