Variants

python-chess supports several chess variants.

>>> import chess.variant
>>>
>>> board = chess.variant.GiveawayBoard()

>>> # General information about the variants
>>> type(board).uci_variant
'giveaway'
>>> type(board).starting_fen
'rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w - - 0 1'

See chess.Board.is_variant_end(), is_variant_win() is_variant_draw() is_variant_loss() for special variant end conditions and results.

Variant	Board class	UCI	Syzygy
Standard	chess.Board	chess	.rtbw, .rtbz
Suicide	chess.variant.SuicideBoard	suicide	.stbw, .stbz
Giveaway	chess.variant.GiveawayBoard	giveaway	.gtbw, .gtbz
Atomic	chess.variant.AtomicBoard	atomic	.atbw, .atbz
King of the Hill	chess.variant.KingOfTheHillBoard	kingofthehill
Racing Kings	chess.variant.RacingKingsBoard	racingkings
Horde	chess.variant.HordeBoard	horde
Three-check	chess.variant.ThreeCheckBoard	3check
Crazyhouse	chess.variant.CrazyhouseBoard	crazyhouse

chess.variant.find_variant(name)

Looks for a variant board class by variant name.

Chess960

Chess960 is orthogonal to all other variants.

>>> chess.Board(chess960=True)
Board('rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1', chess960=True)

See chess.BaseBoard.set_chess960_pos(), chess960_pos(), and from_chess960_pos() for dealing with Chess960 starting positions.

UCI

Stockfish and other engines allow you to switch variants by setting the UCI_Variant option.

>>> import chess.uci
>>> import chess.variant
>>>
>>> engine = chess.uci.popen_engine("stockfish")
>>>
>>> board = chess.variant.RacingKingsBoard()
>>> engine.setoption({
...     "UCI_Variant": type(board).uci_variant,
...     "UCI_Chess960": board.chess960
... })
>>> engine.position(board)

Syzygy

Syzygy tablebases are available for suicide, giveaway and atomic chess.

>>> import chess.syzygy
>>> import chess.variant
>>>
>>> tables = chess.syzygy.open_tablebases("data/syzygy", VariantBoard=chess.variant.AtomicBoard)