Hnefatafl
The game is for two players, and each has a different aim; one is attacking and besieging, the other is defending and escaping.
History
Hnefatafl was a popular game in medieval Scandinavia and was mentioned in several of the Norse Sagas. Some of these saga references have contributed to controversy over the possible use of dice in playing hnefatafl. The rules of the game were never explicitly recorded, and only playing pieces and fragmentary boards have been found, so it is not known for sure how the game was played. If dice were in fact used, nothing has been recorded about how they were used. Archaeological and literary sources indicate Hnefatafl may have been played on a 13×13 or an 11×11 board. It became a popular game in Northern Europe during the Viking era (end of the 8th Century to 1000 CE. When chess became a popular game during the Middle Ages, the rules of Hnefatafl were forgotten. 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. The game developed differently at different locations. Archaeologists have found editions in places such as Ireland and Ukraine. It was last recorded to have been played in Wales during 1587 and Lapland in 1723.
Several sets were found in Bjorko, on the island of Birka in Sweden. These include a set of twenty-seven gaming pieces of lathe-turned bone with an iron mounted wooden gaming board in grave 624. The pieces are spherical with flat bases, and the bases contain the remains of iron pegs, used to insert the pieces into the holes of a peg-holed gaming board. The king is 3 cm high and capped with a bronze mount to distinguish him from the other pieces (2cm). Six of the pieces are smaller in size than the rest. Twenty-five bone or horn hemispherical pieces were found in Birka grave 886, a set of eight black with a white spiral pattern glass gaming pieces from grave 710 and a a set of twenty-five ninth century spherical gaming pieces with flat bases, made of glass, accompanied by a glass king piece in grave 750. The spherical pieces are 2.5 cm to 2.7 cm high, with eight of dark green glass and seventeen of light blue-green. The king is dark green, and is shaped with a conical body topped with a round head, the head being decorated with eyes, a nose and a crown.
The Birka sets
The Board
Set the pieces out with the attackers arranged in groups of 6 at each side of the board, making a total of 24 and the 12 defenders arranged around the king (crossed circle) in the centre of the board.
The dark pieces are the attackers; they move first. Their aim is to prevent the king escaping to one of the corner (crossed) squares, and to box him in on all four sides so that he cannot move at all. The aim of the light pieces is to avoid siege and manoeuvre the king to one of the corner squares.
All pieces move in the same way, along rows of squares in any direction, like the rook (or castle) in chess. They do not move diagonally. They may be moved as many spaces as are free but may not jump over other pieces. The central square is the king's square and no other pieces may occupy it, though they may pass over it.
Sandwiching one piece between two of the opponent’s captures pieces, however a piece moved deliberately between two of the opponent's pieces is not taken. The king cannot itself be taken in this way but may take part in taking other pieces. The king is taken if it is surrounded on all four sides.
Special situations
If the light pieces encircle the king and all the remaining dark pieces, they win; for although they may not be able to prevent movement inside the circle, they prevent the king from escaping and so achieved their aim.
Any piece except the king is taken if it is trapped against one of the corner squares.