In Norse religion, Mjölnir is the hammer of Thor, the god associated with thunder and the protector of mankind. Mjölnir is one of the most fearsome and powerful weapons in existence, capable of leveling mountains.
The game is one of pure strategy, played on a square board. A king and a small force of defenders occupy the centre of the board. A larger force of attackers, twice as numerous as the defenders, occupy positions around the edge of the board.
The objective of the king is to escape to the periphery of the board, while the objective of the attackers is to capture the king, preventing his escape. The pieces move orthogonally, like rooks in chess, and capture is by surrounding a piece on two opposite sides.