This game differs from usual Chess in that Queens are replaced by Golems, which move two in any direction, but must be captured twice to be removed -- the first piece that captures them is itself captured. A Golem that captures another Golem is reduced to a 1/2 Golem.
 
Golems can only capture other Golems under restricted conditions. This makes them hang around longer and makes the game less likely to turn into a game of usual Chess (although if both Golems are captured, the possibility of a Pawn promoting to a Golem can still make a big difference).
 
A longer, more detailed description of Golem Chess can be found at http://www.chessvariants.com/diffmove.dir/golem-chess.html.