This is an Irish version of Hnefatafl, which uses the smallest board.
White's goal is to get
his king safely to one of the corners of the
board; Black's goal is to capture White's king.
The center square is called the throne and only the king may occupy
it; but any piece may pass over it.
All pieces move like
chess rooks. All pieces are captured custodian-wise:
by surrounding a single piece on two opposite sides, either
horizontally or vertically;
The corners or empty throne count as hostile pieces for the purposes
of capture, except that
the king cannot be captured using the throne.