When an opponent accepts the invitation, a game board starts up with both players with a beep.
With an invitation you can meet an opponent from whereever in the world, but you could of course also arrange with a friend to meet for a game of Hnefatafl over the internet.
NB: Both Java and Javascript must be enabled in the browser.
When the king is captured from 2 sides: King's square rule 1: King's squares are hostile to all pieces.
King's square rule 2: King's squares are hostile only to the attackers (Trebeta).
When the king is captured from 4 sides: Edge rule 1: The king can be captured on the board edge.
Edge rule 2: The king cannot be captured on the board edge (Shetland Fetlar). Hammer/anvil rule 1: The king can capture both as hammer and as anvil.
Hammer/anvil rule 2: The king can capture as anvil but not as hammer (Shetland Unst).
Throne rule 1: The king can return to the throne, and pieces can move through the throne.
Throne rule 2: The king cannot return to the throne, and pieces cannot move through the throne (Ashton).