King Billy's War is a postcard game of the Williamite War in Ireland 1689-91 between the Catholic supporters of King James II and the Protestant followers of King William III. The Jacobites (7 brigades in green) are mostly Irish with some good cavalry and French infantry. The Williamites (10 brigades in orange) are a mix of Ulster Presbyterians and English, Dutch, Danish and Huguenot troops. The two players control brigades and move them from point to point across Ireland. The Jacobites begin with the advantage, but the Williamites have large reinforcements and will predominate in the second half of the game. If either side can win control over all of Ireland they win, otherwise the game is a draw.