The game can be played on a board with 7×7, 9×9, 11×11, 13×13, 15×15 or a 19×19 squares. The center often has special markings.
A beautiful carved board with 13×13 squares was found at Gokstad in Norway. This is a double-sided board with a nine men’s morris layout carved on the reverse side as with other less impressive examples. Many other wooden tafl boards have also been found throughout the Viking and Anglo-Saxon world, but some of the boards were much simpler affairs being only marked out with charcoal or scratched onto the surface of slices of rock.
The pieces for these games were usually hemispherical. For boards with 9 squares a side, 16 light and eight dark pieces were used, with an additional king. Boards with more squares used 24 light, 12 dark and a king (hnefi or cyningstan).
Although by the later Middle Ages chess had taken over, hnefatafl still survived in Wales and is described in a manuscript of 1587. It was then called tawlbwrdd and was played on an 11×11 board with 24 light pieces, 12 dark pieces and a king.
The ‘king’ moves first. He has half the number of pieces his opponent has (6/12 in the 7×7 version, 8/16 in the 9×9 version, 12/24 in the 11×11 and 13×13 version, 24/48 in the 19×19 version. He wins the game if he can manage to get his ‘king’ out into one of the corner squares (the large 19×19 version often allows the king to win if he can reach the edge of the board). His opponent can win by trapping the king.
All the pieces move in straight lines like the rook or castle in chess, and a piece may be moved any number of squares providing no other piece is standing in the way. It may not pass over another piece. A piece is taken by making a move which traps it between two of your pieces, but not on any diagonal. It is possible to take two opposing pieces at the same time. A player is also permitted to move between two opposing pieces without being taken.
The king can normally only be trapped if he is surrounded by four pieces unless he is on the edge of the board where only three would be needed to ‘surround’. The four corner squares (which are sometimes decorated) may only be occupied by the king. This is the same for the center square. Opponents may cross over it, but not land on it. The king may not be captured while standing on the center square.