What happens when an aerospace engineer decides to take chess to the next level? Three-player chess.
In 1972, Robert Zubrin (the same man responsible for establishing the Mars Society) was awarded a patent for the game. This chess variant is just one of more than two thousand variations on the game, and just one of many three-player variants.
A New Challenge
In three-player chess variants, players use a non-standard board – usually a hexagonal one – with three armies.
Movements for the individual pieces are essentially the same as in traditional two-player chess. The design of the game involves a few differences, though.
The cells on the playing field are usually hexagonal or quadrilateral, but not square. Some versions even use triangular cells. The board that uses hexagonal squares also contains three bishops per side in order to cover all of the cells.
![[Image Source: Dr Jacek Filek Wikimedia Commons]](https://images.interestingengineering.com/images/import/2017/03/3-player-chess.jpg)
The Rules
You may be asking yourself, how is three-player chess fair? Couldn't two players easily gang up on the third to take them down?
Theoretically, yes. Chess variants are very difficult to design fairly. For most common three-player chess variants, the winner is simply the player who is the first to deliver checkmate. The other two players lose, or the player who wasn't checkmated gets half a point.
In the version created by Zubrin, players use a board with 96 cells. Kings are captured, and the last-remaining king wins. The pieces of whatever player is eliminated remain on the board and may be captured.
Not only are you constantly worried about having your pieces taken down from two other players, but you get to watch the carnage of other players attacking each other as well. It brings the fun of watching and playing a game of chess into one.
Historically speaking, there are other ways to play three-player chess other than being "first to checkmate." Famously, there was a "neutrality rule" introduced in the mid-2000s by Ilshat Tagiev. This rule states that whoever's turn it is can only attack the enemy if he or she was attacked by that enemy in a previous move, or if the opponent was not attacked by the third player on its previous course.
This rule prevents two players from chasing a third and is considered an important innovation in three-person chess.
Interested in testing your skills against a duo? There's an online version of three-player chess.