I am delaying my rating in case this variant is altered or tested. This is simular to Toroidal Chess which is played on a 64 square board (8x8). Toroidal Chess is useless as a game as it presents a major problem in that conditions for checkmate can be quickly reduced to improbable to none. For instance, a single queen and king cannot checkmate a single king. Also a rook, bishop, or queen can be moved through a clear path across the board and right back to the same square that it started at (effectively a pass). Read Chess & Mathematics (Шахматы и математика) by Гик Е.Я. for the problems presented by Toroidal Chess. I suspect, though I have not calculated, that Torus Chess presents the same problems but takes longer to arrive at them. It could be tested by modifying one of the Libre chess simulators. See just how often the game resulted in a draw. I suspect even mismatched AI players would often draw. But I have some a suggestions. First, disallow the 'pass' move. Moved pieces must always move to a different location. Also, clearly differentiate the pawns going forward from the backward pawns (for the sake of amateurs and spectators). Clearly mark the promotion rows for each type of pawn. Most important, what is needed to avoid the vast majority of draws, is a piece that cannot be removed from the board. It also speeds up and punctuates the game by adding occasional surprises and forces the player to rely on improvised strategies and skill more than any established strategies. This could be considered good or bad. The Assassin. First, the assassin begins invisible. This presents unique playing arrangements for a live game, but is easily handled in electronic versions. One of the queens is replaced with a blank square where the assassin is. When a player moves his assassin, it is done on a small hidden board and is watched by a witness or is verified by the player's honor. Each player has their own hidden assassin board. Obviously, the other player will know when his opponent moves his assassin. And the witness must verify the player actually moved it. Depending on what move set the assassin uses, one could move a piece right back to were it started in a single turn. This should not be allowed, but should be carefully considered if this should be allowed as a way to turn the assassin invisible (making a complete move) without altering its position. The assassin can only actively attack the king, therefore serves the only two reliable purposes of check or checkmate. Using the assassin for check or checkmate, renders the assassin visible. Several move sets could be used. The moves of the king, the moves of the knight, both, 2 consecutive moves of the kings. Or one set for moving and another for attacking the king. Running it through a simulator could reveal what worked best. The main point of the assassin is that it cannot be removed from the board. If a piece contacts (when visible or invisible) it by moving over or landing on it, that piece is removed before the next turn. Note, a piece could successfully move over an assassin and successfully attack another in the process (removing the attacked piece from the board), but this is the last thing that piece will ever do. When a piece passes over an assassin, it loses its invisibility until it moves again and regains its invisible status. If one assassin lands on or attempts to more over another, both become visible and the moving assassin is returned to its original position and the player makes a different move with the assassin or another piece. Pawns cannot be promoted to assassins.