What is Hnefatafl
Hnefatafl was a popular game in medieval Scandinavia and was mentioned in several of the Norse Sagas. The rules of the game were never explicitly recorded, and only playing pieces and fragmentary boards still exist, so it is not known for sure exactly how the game was played.
It became a popular game in Northern Europe during the Viking era (8th to 1000th century AD), a turbulent time full of violent conflicts, but when chess became a popular game during the Middle Ages, the rules of Hnefatafl were forgotten over time.
Hnefatafl was particularly popular in Nordic countries and followed the Viking civilization to other parts of Europe, primarily to the British Isles and the Viking country of Gardarike in what is now part of Russia.
The attackers (shown as black) lay seige, their goal, to capture the chief. The defenders (shown as white) must break the seige and get their chief (shown as white with mark) to safety.
The defenders and the attackers. There are twice as many attackers as defenders.
layout at start
The attackers' side moves first, then the players take turns.
All pieces move any number of vacant squares along a row or a column, similar to a rook in chess. This piece may not jump over nor land on any other piece
All pieces except for the chief are captured if sandwiched between two enemy pieces, or between an enemy piece and a restricted square. The two enemy pieces should be on the square above and below or on the squares to the left and right of the attacked piece, but not diagonally.
A piece is only captured if the trap is closed by the aggressor's move, it is therefore permitted to move in between two enemy pieces with no consequence.
The chief may also take part in captures.
piece is captured
piece not captured
Restricted squares may only ever be occupied by the chief. The central restricted square is called the throne. It is allowed for the chief to re-enter the throne, and all pieces may pass through the throne when it is empty.
Restricted squares are hostile, which means they can replace one of the two pieces taking part in a capture. The throne is always hostile to the attackers, but only hostile to the defenders when it is empty.
The four corner squares are also restricted and hostile, just like the throne.
The board edge is NOT hostile.
If the chief reaches any corner square, the chief has escaped and the defenders win.
The attackers win if they can capture the chief.
The chief is captured when the attackers surround him on all four cardinal points, except when he is next to the throne.
If on a square next to the throne, the attackers must occupy the three remaining squares around him.
The chief cannot be captured on the board edge, UNLESS he is the only white piece remaining on the board and is completely surrounded by black.
chief not captured
If the attackers surround the chief and ALL remaining defenders, then they win, as they have prevented the chief from escaping.
If a player cannot move, he loses the game.
If the game does not end within two hours, it is a draw.
If it is not possible to end the game, for example, because both sides have too few pieces left or because of repetitions, it is a draw.