Commit your queen's move and arrow blind, then reveal at once, twin arrows cancel and clash.
Each round you secretly pick one amazon, move her like a chess queen, then fire an arrow from where she lands to burn a square forever. Your opponent commits a blind move too, and both reveal and resolve at the same instant. Wall the enemy in while keeping your own room, a side with no legal move after the reveal loses.
The Game of the Amazons was invented in 1988 by Walter Zamkauskas of Argentina: move an amazon like a chess queen, then fire an arrow from where she lands to burn a square forever, and whoever runs out of legal moves loses.
The original change is that both players commit blind and reveal at once, making it a simultaneous game rather than a turn-taking one.
Amazons is a territory game whose whole craft is counting the space each side has left. Simultaneity means you are counting a board that has not happened yet, so a sealing move can be wasted on a square the opponent was already abandoning — and two players can burn the same square between them.
Amazons Ante takes the traditional abstract Game of the Amazons and makes both players move at once, adding bluff and clash to a pure territory game. It is an original, free browser game on PlayPendium with CPU and pass-and-play modes.