Multiplayer chess for hexagonal variants
Multiplayer chess variants have existed since the beginning of the game, as chaturaji was a four-player version of chaturanga. Multiplayer chess introduces a diplomacy factor, turning the game into a quite a different one from two-player chess.
In 1984, Ronald Planesi invented the ImmortalStarMasters game. It is a chess or checkers variant for two to six players played on a hexagonal board.
The original 1984 name of this game was Kingmaster., however, due to the U.S. Copyright Office's lack of support for title copyright protection, and asserted infringement, the name was changed. The board in this game is significantly larger than in Gliński's hexagonal chess in order to accommodate six players and placed in a such a way that each side of a large hexagon may be occupied by one of six players. Pieces are arranged essentially along traditional lines (bishops and knights exchange places to account for the hexagon variation) and one extra bishop is added so all spaces on the board are covered by bishops (a ninth pawn is also added to "seal" the third bishop within the initial structure). All pieces except pawn move in the same way as in Gliński's hexagonal chess. The pawn moves and captures similar to McCooey's chess, but within an individual territory a pawn can move in two forward directions and capture in three directions (one directly forward direction and two diagonally-forward directions), due to the particular orientations of a hexagon. In the central area pawns can move and capture in any direction.
Napoleonesque methods of play include two players each using three sets of pieces or three players each using two sets of pieces. The primary structural difference between ImmortalStarMasters and the listed hexagonal variants, other than the critical size of the board, is that the listed variants all allow a bishop to exit the initial structure as its first move without movement by any pawns whatsoever (concurrently meaning that a bishop is unprotected by any pawns and subject to immediate attack without the prior movement of a protecting pawn), which is an extreme violation of basic chess structure logic.
A two-player version uses essentially the same rules and can use the same board, but a smaller board is available and recommended for closer adherence to "number of pieces versus available space" (powers of force) considerations to match the "difficulty of play" as related to standard square-based chess.