How it is played
Everything moves like a rook — any distance along a rank or file, never diagonally, never through another piece.
The defenders get the king to any corner and win. The attackers surround the king on all four sides and win.
You capture by sandwiching an enemy between two of your pieces. Moving into a sandwich yourself is safe. The corners and the empty throne count as a wall for either side.
Only the king may stop on the throne or a corner, though anyone may pass over the empty throne.
These are playable versions, not reconstructions. All three use corner escape, though Linnaeus's Tablut and most Brandubh reconstructions let the king out at any edge. Shield walls and exit forts are not implemented.