Three-Person Chess is a chess variant designed by Sheldon which appeared in The Wildebeest Implementation. It utilizes a non-standard, three-sided board with transitional quadrilateral to triangular tessellation to solve the balanced centre combat-area problem, additional (or fairy) pieces, and different rules for capture, move order, and game objective, etc. It is assumed that the original pieces are also kept - the bishop, the rook, the pawn and the queen definitely are.
The known pieces invented by Sheldon are:
- Serpent and Old Woman: The first pieces invented. When the serpent slithers to an opposing player’s piece, that piece is considered poisoned and will die after two more moves. Unless, it gets to the old woman in time, in which case she sucks out the poison, turning her into the Grand Empress, a piece combining the power of the knight, queen and serpent. Sheldon plays this version with imaginary replicas of himself.
- Prince Joey: The King’s feeble-minded but well-meaning cousin. The fun thing about Prince Joey is every time he moves, there’s a one-in-five chance he’ll kill himself.
- Catapult: Can fling pieces. Unknown whether it can fling all pieces (but it can definitely fling a bishop) or anything else about it.
- Gorilla: Nothing is known about this piece, but the space "Queen's Gorilla Two" is mentioned.
- Transporter Pad: Moves pieces from one space to another. Unknown whether it can transport all pieces (but it can definitely move a rook) or anything else about it.
- Golf Cart: This can (assumedly) be equipped to any piece (in the show Leonard asks when the pawn can use it). It can be used when it is finished charging or when the player lands on the time machine.
- Time Machine: When the golf cart lands on the time machine, pawns can use it. It is unknown if the time machine can move or whether it can be used for anything else.
- The Beekeeper: Nothing about this piece is known, apart from the fact that it can release a swarm (which can cause checkmate), move and capture a pope.
- The Pope: Nothing about this piece is known, apart from the fact that it can be captured by the Beekeeper.
- Jet Pack: This piece can be equipped to the Pope, and probably any other piece. It is unknown what it does, but judging by the name it might allow pieces to hover above the board or fly to different spaces.
The final revised game is played by Sheldon, Leonard, and Howard, while Raj waits to play the two victors. In this match, Sheldon employs a catapult to fling his bishop to Howard’s Queen’s Gorilla two. Howard then moves his rook to a transporter pad and comes out at Leonard’s Queen’s Bishop five-and-a-third, placing Leonard in check. After Leonard inquires when a pawn is allowed to use the golf cart (to which Sheldon informs him when it’s done charging or you land on the time machine), Leonard moves his Beekeeper to King 12, capturing Sheldon's Pope and releasing a swarm for a checkmate on Sheldon. Disappointed, Sheldon wishes he had given his Pope a jet pack. (The Wildebeest Implementation)
Trivia
"Three-player chess" [1] does exist in reality; of course, the version that was invented by Sheldon was a rather exaggerated one compared to its analogues in reality.