+Squatter Chess: safe on last rank = win
+Companion Chess : pieces of same nature don't attack each others
+Medusa Chess = Isardam
+Crossing Chess = win when the king cross half-board
+Kingmaker: pawns can promote also into enemy king
+Eightkings: 8 pawns + 8 kings (non-royal until the last remains?)
+Crown Chess: place all units on move 1 (similar to Sittuyin, more freely)
+