Hnefatafl - Viking chess

Hnefatafl is an old board game that was popular in medieval Scandinavia. It was also popular in Northern Europe during the Middle Ages but declined with the introduction of chess. The game disappeared and the rules to the game were lost. Discovery of playing pieces and boards lead to the modern reconstruction of the game and rules in the early 20^th century.

Unlike chess, one side is playing defense (white) and the other offense (brown or black). The game is similar to one aspect of chess in that all moves are, like the rook in chess, orthogonal. An unusual aspect of the game is the asymmetry of the opposing sides. The defensive side has 12 "soldiers" and a King; the offensive side has 24 soldiers. The offensive side can capture (and remove from the board) a white piece by moving a piece so that it and another offensive piece are on either side of a white piece. White can also capture opponents pieces. 

For the King to be captured, he must be surrounded on four sides, which is the goal of the offensive team. The goal of the defensive team is for the King to move from his initial central position to one of the four corners while avoiding capture. If the King succeeds in moving to one of the four corners, the white team wins.The game is now readily available.