Fidchell

' (in Irish; also spelled , , or , and pronounced in Old Irish) or ' (in Welsh, pronounced ) was an ancient Celtic board game. The name in both Irish and Welsh is a compound translating to "wood sense"; the fact that the compound is identical in both languages demonstrates that the name is of extreme antiquity. The game is occasionally claimed to be a predecessor of the modern game chess. The game was played between two people who moved pieces across a board; the board shared its name with the game played upon it. The name has evolved into , the Irish word for chess; the similar is the name for chess in modern Welsh.
History.
 or is mentioned often in ancient Celtic legends and lore, but the exact form of the game is open to speculation, due to lack of detail on the rules, playing pieces, and the board. What is clear is that it was played on a board, with opposing sets of pieces in equal numbers. It should not be confused with games like or (also called ), which involved a king in the centre and pieces in a 2:1 ratio. 
One text reads, "", 'Half its pieces were of yellow gold, the other half of white bronze", suggesting that was played by equal forces. The Roman board game ("game of little soldiers") was also played with pieces of equal numbers; is known from post-Roman Britain, and it is possible that was a descendant of .
The legends describe as a game played by royalty, and by the gods. In legend, it was invented by , god of light and inspiration, and was played skilfully by his son, the hero . A series of games forms an important episode in .
Lavish, sometimes mystical boards appear often in medieval Welsh literature. In "The Dream of Rhonabwy", a prose tale associated with the , King Arthur and play the game with golden men on a silver board. In another prose tale, "The Dream of", the character is carving men for his golden board when he is visited by the emperor . The board of is named as one of the Thirteen Treasures of the Island of Britain in lists dating from the 15th and 16th centuries; according to the lists the board is gold and the men silver, and the pieces play against each other automatically. A magic comparable to 's appears in the Arthurian romance "Peredur son of Efrawg"; a number of French versions of the Holy Grail story feature similar chessboards with self-moving pieces, following the Second Continuation of 's "Perceval, the Story of the Grail", though in these only one side moves, while the hero plays the other.
Gameplay.
Although is mentioned often in legend and myth, it is still largely unknown how the game was played. There are two main theories regarding the rules and board layout. One is that is a variant of the Welsh game , itself descended from the Norse games. These games, along with the Irish , are played on a grid, often seven squares by seven, with the king in the middle. The king has a number of defending pieces around it at the beginning of the game, and they are surrounded by twice as many attackers. The object is to make a clear path for the king to the edge of the board, while the attackers must attempt to surround, and thereby capture, the king.
This theory is supported by an artefact found in Balinderry, County Westmeath in 1932, known as the Ballinderry Game Board. This is of a wooden board with Celtic symbols on it, with a seven-by-seven grid, marked off by 49 holes. This artefact may be a variant, and perhaps even a board; many commentators assume that it is the type of board upon which one would have played . Reconstructions of probable rules proceed from there.
However, there are a few difficulties with this commonly accepted view. First, the variants are usually played with unequal numbers of pieces, the attackers being twice as numerous as the defenders. seems likely to have been played with equal numbers on both sides. Secondly, some claim that the games, especially , were often played with a die, made of a sheep's knucklebone, and this feature seems absent in . In Wales, a clear distinction is made between and , which, if also true of Ireland, would tend to indicate a similar distinction between and .
Historical impact.
, as described in the legends, often has a mystical or divinatory aspect to it. Battles ebb and flow as a result of the ebb and flow of a game of , games play themselves, great events are decided on the outcome of a match. This supernatural aspect is not as clearly reflected in the games. 
There is clear archaeological and textual evidence that a variant was played in Ireland in ancient times. What is not quite as certain is that this game was .