Heisenberg is connection game played on a square grid. Two players, Black and White, alternate placing stones on the intersections of the grid until one player connects his two sides of the board and wins the game.
Object of the game
A player wins when he forms a chain of his own stones which connect his two edges of the board. The chain can be connected orthogonally and diagonally.
On a normal turn, a player places one stone of his own color on an empty intersection of the board. The stone must have orthogonal access to both of that player's board edges. That is, it must be possible to trace a route from that intersection to each of the player's own board edges without moving diagonally or passing through an opposite-colored stone.
If at the beginning of a player's turn any of his stones do not have access to both of that player's board edges, he must pick up all such stones and redeploy them. The stone(s) may be placed on any empty intersection(s) of the board where they have access. He does this instead of his normal placement.
—description from the designer