Community variant
Great-grand chess
Grand chess on a 12x10 board.
This is a user-catalogued casual variant. Technical details such as board size, FEN, pieces, and hand rules are defined in the Fairy-Stockfish variants.ini block below.
Generated rule overview
This variant is defined directly from a Fairy-Stockfish rule block. The text below is generated from the available configuration and may omit details that are only implicit in piece movement notation.
Board and setup
Pieces and movement
- The piece set used on the board is: king (k), queen (q), rook (r), bishop (b), knight (n), pawn (p), archbishop (a) and chancellor (c).
Move rules
- A piece may not move to a square where it would have no legal future movement.
Promotion
- Promotions are available in the configured promotion zones. The the promotion region for White is all the ranks from 8 to 10 and the promotion region for Black is all the ranks from 3 to 1.
- The pieces that can promote are: pawn (p).
- Promotion choices are both sides: knight (n), bishop (b), rook (r), archbishop (a), chancellor (c) and queen (q).
- Pawn promotion is optional where promotion is legal.
- The number of promoted pieces of some types is limited.
Fairy-Stockfish rules
[great-grand_chess]
variantTemplate = fairy
pawn = p
knight = n
bishop = b
rook = r
archbishop = a
chancellor = c
queen = q
king = k
maxRank = 10
maxFile = 12
startFen = r10r/1nbacqkcabn1/pppppppppppp/12/12/12/12/PPPPPPPPPPPP/1NBACQKCABN1/R10R w - - 0 1
doubleStepRegionWhite = *3
doubleStepRegionBlack = *8
promotionRegionWhite = *8 *9 *10
promotionRegionBlack = *3 *2 *1
promotionPieceTypes = nbracq
promotionLimit = q:1 c:2 a:2 r:2 b:2 n:2
mandatoryPawnPromotion = false
immobilityIllegal = true