This is the kitchen sink of chess. Fourth order chess allows a player to use all the strategy pieces in the 3rd and 4th order (the full army). Like chess in the 3rd order, strategy pieces cannot be rearranged or swapped. Players have the option to play an alternate version of chess called Pawn King. The primary version of Pawn King allows the Prince to be promoted to a King. In a secondary version, Upper Royal pieces create pawns (from the opponents capture pool) upon the capture if enemy pieces. Re-introduced pawns will be placed at the bottom of the file of capture.