Ard Ri rules

The game in short

Seven squares by seven. Sixteen attackers packed around the rim against eight defenders and their king in a solid block at the centre. The attackers move first. The defenders win by getting the king to a corner; the attackers win by taking him.

The board is more than half full at the start, and no piece can travel further than one square in a turn. Expect a slow, congested game in which lines open a square at a time.

Setting up

Files a to g, ranks 1 to 7. The throne is d4 and the corners are a1, g1, a7 and g7.

Sixteen attackers stand as four groups of four, three abreast at the middle of each edge, with a fourth man stepped in behind them.

• South: c1, d1, e1, with d2 behind.
• North: c7, d7, e7, with d6 behind.
• West: a3, a4, a5, with b4 behind.
• East: g3, g4, g5, with f4 behind.

Eight defenders fill every square of the three by three block around the king, who begins on the throne at d4: c3, d3, e3; c4, e4; c5, d5, e5.

Movement

This is the rule that makes Ard Ri what it is. Every piece on the board, the king included, moves exactly one square along a rank or a file, onto an empty square. There is no sliding, no diagonal move and no jumping.

Only the king may end a move on the throne or in a corner. Once he has left the throne, other pieces may cross it — which, with single-square moves, means simply that they may not stop on it.

Capture

Custodial and active, as everywhere else in the family. Step a piece so that an enemy is caught between it and another of your pieces along a rank or a file, and the enemy is removed. A piece that steps of its own accord into a gap between two enemies is safe. A single step may capture on more than one side.

Each empty corner is hostile to both sides, and so is the throne while it is empty. While the king is on the throne, that square is hostile to the attackers only.

The king is armed and captures like an ordinary defender. On a board this tight, that matters more than it sounds.

Winning

• The defenders win if the king reaches any of the four corners: a1, g1, a7 or g7.
• The attackers win by occupying all four squares orthogonally next to the king, counting a hostile square as one of the four. As in the eleven by eleven codes, this means a king standing on the edge of the board cannot be captured there.
• A side with no legal move at the start of its turn loses. With sixteen attackers on a seven by seven board, this is a real possibility rather than a formality.

There is no shieldwall, no edge fort and no encirclement.

It is worth repeating that these conditions were not handed down by anybody. They are the terms the circulating description states, applied consistently with the rest of the tafl family, and nothing here should be read as a claim about how a medieval game was played.

Repetition and the move limit

• A player about to repeat the same position for the third time must play something else, and loses if they will not.
• A hundred moves without progress draws the game. On a board this congested the limit does real work, and shuffling is a genuine risk for both sides.

Sources

Everything on this page is written from scratch. These are the works it leans on, and what each one settles.

• The circulating modern description of Ard Ri

  The account found in twentieth-century games books and in software, which is the only source for this game. It settles the board, the armies and the single-square move used here. It is not supported by any medieval text, and this site treats it as a reconstruction.

• H. J. R. Murray, A History of Board-Games Other Than Chess, 1952

  The standard survey of the tafl evidence. Its value here is negative: it is the place to see what the sources for Irish and Scottish tafl actually contain, and Ard Ri as played today is not among them.