Tafl: viking chess

1. The attackers (black) move first.
2. All pieces move like a rook — any distance in a straight line, no jumping.
3. Capture a piece by trapping it between two of yours (or one of yours and an empty throne).
4. Defenders win by escorting their king out to a corner or the board's edge (depending on the variant); attackers win by surrounding him.

Tafl: viking chess is an asymmetric board game from the Viking age. One side defends a king and tries to get him out, while the larger attacking side tries to surround and capture him. All pieces move like a rook in chess — any distance in a straight line, without jumping — and a piece is captured when it's sandwiched between two enemies. Several variants are included, with boards of 7, 9, 11 or 13 squares a side and different rules for whether the king must reach the edge or a corner, whether he's caught from two sides or four, and how many pieces each side gets. Play the computer, a friend on one device or an online opponent. As the attackers, sealing off the corners early makes the king's escape much harder.