Rules

To play Hnefatafl one player will take the role of the attacker, leading a group of 24 warriors on a mission to capture the enemy king. Another player will take the role of the defender and, with only 12 warriors, escort the king to safety.

Setting up

The attacker must place his pieces (those with swords) on the designated spaces on the edges of the board. The defender must place his pieces (those with shields) on the designated squares on the center of the board. This king, the piece with a singular shape, must be placed on the space on the very center of the board, on top of the crown.

The game

The attacker is the first to move, and then they alternate turns. The goal of the attackers is to capture the enemy king (as explained bellow). The goal of the defenders is to lead their king to one of the refuge squares, in the corners of the board.

Moving

All pieces, the king included, may move as many spaces as they wish, until they find an obstacle (be it another piece, a refuge square or the end of the board). Although all pieces may move across the central square, only the king may land there. The same thing is true about the refuge squares (the spaces on the corners of the board): only the king may land on those. If the king lands on any of the corner refuges, the game ends and the defender is the winner.

Capturing

When a piece is captured, it is immediately removed from the game. To capture an enemy piece it is necessary to sandwich it with two allied pieces, a move known as "the hammer and anvil". It is not possible to capture if the allied pieces are not aligned vertically or horizontally, nor if they aligend diagonally. A piece is also not captured if it itself have moved into the sandwiched square.

It is possible to capture an enemy piece by sandwiching it with an allied piece and a refuge square. It is also possible to do so by sandwiching it with an allied piece and the center square (where the crown is), but this will not work to capture a defender if the king is on that square. The above rules do not apply to the defending king. It can only be captured if it is surrounded by four attackers, one on each side (so it cannot be captured if it is on a square by the edge of the board). If the king is captured, the game ends and the attacker wins.

The king may also capture, and it is possible to capture up to three pieces with one move.

Draw game

The game ends in a draw if the same exact positions are repeated by the same exact pieces thrice. It also ends in a draw if any player has no valid moves.