The box reads:
In this 2 or 3 player game, the objective, when the 36 Cauldrons have finally finished being shuffled around, is that you end with the largest connected group. But beware! Even one of the group finishing adjacent to the Poison Pot nullifies the whole group.
The mechanic is that the board starts empty except for the Poison Pot. Then, on each turn one pot existing is moved, and a new pot is drawn at random, evaluated, and placed on the board.