+"Ball" Chess: 9x9 board, ball on center square. 2 queens ?
+To take the ball when it's free you need to capture it.
+To take the ball when it's used, u need to take the piece.
+Goal: bring ball to final rank.
+Possibles passes : soit à une pièce, soit sur une case.
+ --> remplace un déplacement de pièce. Par exemple pion a2 passe à cavalier a4 = 1 coup.
+ --> selon le mode de déplacement standard (donc tout droit pour les pions)
+Pas de notion d'échec ou de mat (?)
+Si une pièce est mat elle donne le ballon (?)
+
+Landing pieces from empty board:
+https://www.chessvariants.com/diffsetup.dir/unachess.html
+
+Rugby http://www.echecspourtous.com/?page_id=7945
+
+Cannibal Chess with forced captures.
+
+Knightrelay: implement "official" version as Knightrelay v1
+
+Antiking: implement v1 (deterministic) https://www.chessvariants.com/diffobjective.dir/anti-king-chess.html
+
+S-chess https://en.wikipedia.org/wiki/Seirawan_chess
+
+Generator variant, called "Matrix" ?