Tablut

The king must flee, the attackers must surround him.

The tafl game described by Linnaeus in Lapland: a king and his eight defenders in the centre, sixteen attackers on the edges. Two sides, two goals, one asymmetric battle.

Players: 1 or 2 players
Length: 15 min

Against the AI
Two players on one device

Play Tablut

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How to play

Goal of the game

The defenders want their king to escape: he wins as soon as he reaches a square on the edge (or one of the four corners, depending on the option chosen). The attackers want to capture the king by surrounding him.

How it works

The attackers (sixteen dark pieces) move first. The eight defenders (light pieces) surround their king, placed on the throne at the centre.
All pieces, the king included, move like a rook in chess: in a straight line, as many free squares as you like, without jumping over a piece.
Throne: only the king may stop on it; other pieces may pass through it when it is empty. In the “Corners” variant, only the king may enter a corner.
Custodial capture: a piece is captured when the opponent sandwiches it on both sides, along a row or a column. The empty throne (and the corners, in the “Corners” variant) counts as an enemy piece. The king takes part in captures. You can safely move in between two enemy pieces.
Capturing the king: he must be surrounded on all four sides by attackers, or on three sides if he is next to the throne. On the edge of the board, the king cannot be captured.
A side that can no longer move loses the game. A position repeated three times, or fifty moves by each side without a capture, is a draw.
Tap a piece then its destination, or drag it. Golden dotted lines mark an open exit for the king.

Tip: as a defender, look for the double threat; a king who sees two exits at once can no longer be stopped. As an attacker, first form a continuous cordon, then tighten the noose. The edge victory clearly favours the defenders; the “Corners” option makes their task harder.

About the AI

Null-window negamax alpha-beta search with iterative deepening, a Zobrist transposition table, killer moves, history and null move. A quiescence search calculates the king's escapes and forced blocks; the evaluation measures the attackers' cordon (escape squares still reachable), the king's paths and double threats, how surrounded he is, and material. Lower levels reduce the depth and add inaccuracies.

AI levels

BeginnerPlays almost at random and often lets the king slip away.
AmateurSees immediate escapes, but not traps.
IntermediateCalculates three plies and spots double threats.
ExpertFive plies ahead: formidable on both sides.
MasterDeep search within a time limit: nearly unbeatable in defence, very tough in attack.