Community variant

Twister chess

Chess but your pieces must move to the square color indicated by the piece ! (currently doesn't work for black)

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.

Uploaded by: Rom142857
Visibility: public
Status: active

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

Default starting position

Pieces and movement

The piece set used on the board is: king (k), queen (q), rook (r), bishop (b), knight (n), custom piece 8 (p), custom piece 7 (x), custom piece 2 (s), custom piece 1 (o), custom piece 3 (v), custom piece 4 (w), custom piece 5 (t) and custom piece 6 (u).
custom piece 8 (p) is a custom piece with Betza movement `mfWcfFinD`.
custom piece 1 (o) is a custom piece with Betza movement `N`.
custom piece 2 (s) is a custom piece with Betza movement `N`.
custom piece 7 (x) is a custom piece with Betza movement `B`.
custom piece 3 (v) is a custom piece with Betza movement `R`.
custom piece 4 (w) is a custom piece with Betza movement `R`.
custom piece 5 (t) is a custom piece with Betza movement `Q`.
custom piece 6 (u) is a custom piece with Betza movement `Q`.
Some pieces have restricted movement regions: mobilityRegionWhiteKnight is a1 d1 e1 h1 c2 g2 b3 f3 a4 d4 e4 h4 a5 d5 e5 h5 c6 g6 b7 f7 a8 d8 e8 h8.
Some pieces have restricted movement regions: mobilityRegionBlackKnight is a1 d1 e1 h1 c2 g2 b3 f3 a4 d4 e4 h4 a5 d5 e5 h5 c6 g6 b7 f7 a8 d8 e8 h8.
Some pieces have restricted movement regions: mobilityRegionWhiteCustomPiece1 is b1 f1 a2 d2 e2 h2 c3 g3 b4 f4 b5 f5 a6 d6 e6 h6 c7 g7 b8 f8.
Some pieces have restricted movement regions: mobilityRegionBlackCustomPiece1 is b1 f1 a2 d2 e2 h2 c3 g3 b4 f4 b5 f5 a6 d6 e6 h6 c7 g7 b8 f8.
Some pieces have restricted movement regions: mobilityRegionWhiteCustomPiece2 is c1 g1 b2 f2 a3 d3 e3 h3 c4 g4 c5 g5 b6 f6 a7 d7 e7 h7 c8 g8.
Some pieces have restricted movement regions: mobilityRegionBlackCustomPiece2 is c1 g1 b2 f2 a3 d3 e3 h3 c4 g4 c5 g5 b6 f6 a7 d7 e7 h7 c8 g8.
Some pieces have restricted movement regions: mobilityRegionWhiteBishop is c1 g1 b2 f2 a3 d3 e3 h3 c4 g4 c5 g5 b6 f6 a7 d7 e7 h7 c8 g8.
Some pieces have restricted movement regions: mobilityRegionBlackBishop is c1 g1 b2 f2 a3 d3 e3 h3 c4 g4 c5 g5 b6 f6 a7 d7 e7 h7 c8 g8.
Some pieces have restricted movement regions: mobilityRegionWhiteCustomPiece7 is b1 f1 a2 d2 e2 h2 c3 g3 b4 f4 b5 f5 a6 d6 e6 h6 c7 g7 b8 f8.
Some pieces have restricted movement regions: mobilityRegionBlackCustomPiece7 is b1 f1 a2 d2 e2 h2 c3 g3 b4 f4 b5 f5 a6 d6 e6 h6 c7 g7 b8 f8.
Some pieces have restricted movement regions: mobilityRegionWhiteRook is a1 d1 e1 h1 c2 g2 b3 f3 a4 d4 e4 h4 a5 d5 e5 h5 c6 g6 b7 f7 a8 d8 e8 h8.
Some pieces have restricted movement regions: mobilityRegionBlackRook is a1 d1 e1 h1 c2 g2 b3 f3 a4 d4 e4 h4 a5 d5 e5 h5 c6 g6 b7 f7 a8 d8 e8 h8.
Some pieces have restricted movement regions: mobilityRegionWhiteCustomPiece3 is b1 f1 a2 d2 e2 h2 c3 g3 b4 f4 b5 f5 a6 d6 e6 h6 c7 g7 b8 f8.
Some pieces have restricted movement regions: mobilityRegionBlackCustomPiece3 is b1 f1 a2 d2 e2 h2 c3 g3 b4 f4 b5 f5 a6 d6 e6 h6 c7 g7 b8 f8.
Some pieces have restricted movement regions: mobilityRegionWhiteCustomPiece4 is c1 g1 b2 f2 a3 d3 e3 h3 c4 g4 c5 g5 b6 f6 a7 d7 e7 h7 c8 g8.
Some pieces have restricted movement regions: mobilityRegionBlackCustomPiece4 is c1 g1 b2 f2 a3 d3 e3 h3 c4 g4 c5 g5 b6 f6 a7 d7 e7 h7 c8 g8.
Some pieces have restricted movement regions: mobilityRegionWhiteQueen is a1 d1 e1 h1 c2 g2 b3 f3 a4 d4 e4 h4 a5 d5 e5 h5 c6 g6 b7 f7 a8 d8 e8 h8.
Some pieces have restricted movement regions: mobilityRegionBlackQueen is a1 d1 e1 h1 c2 g2 b3 f3 a4 d4 e4 h4 a5 d5 e5 h5 c6 g6 b7 f7 a8 d8 e8 h8.
Some pieces have restricted movement regions: mobilityRegionWhiteCustomPiece5 is b1 f1 a2 d2 e2 h2 c3 g3 b4 f4 b5 f5 a6 d6 e6 h6 c7 g7 b8 f8.
Some pieces have restricted movement regions: mobilityRegionBlackCustomPiece5 is b1 f1 a2 d2 e2 h2 c3 g3 b4 f4 b5 f5 a6 d6 e6 h6 c7 g7 b8 f8.
Some pieces have restricted movement regions: mobilityRegionWhiteCustomPiece6 is c1 g1 b2 f2 a3 d3 e3 h3 c4 g4 c5 g5 b6 f6 a7 d7 e7 h7 c8 g8.
Some pieces have restricted movement regions: mobilityRegionBlackCustomPiece6 is c1 g1 b2 f2 a3 d3 e3 h3 c4 g4 c5 g5 b6 f6 a7 d7 e7 h7 c8 g8.

Promotion

Promotions are available in the configured promotion zones. The the promotion region for White is all the ranks from 1 to 8 and the promotion region for Black is all the ranks from 1 to 8.
The pieces that can promote are: knight (n), custom piece 1 (o), custom piece 2 (s), rook (r), custom piece 3 (v), custom piece 4 (w), queen (q), custom piece 5 (t), custom piece 6 (u), bishop (b) and custom piece 7 (x).
Promotion choices are both sides: no pieces.
Fixed promotion mappings: n promotes to o, o promotes to s, s promotes to n, r promotes to v, v promotes to w, w promotes to r, q promotes to t, t promotes to u, u promotes to q, b promotes to x and x promotes to b.
Piece promotion is mandatory where promotion is legal.
Promoted pieces can demote according to the configured promotion mapping.

Piece movement

These diagrams show custom pieces and known Fairy-Stockfish built-in fairy pieces from White's perspective on a compact preview board. Some special moves, especially hoppers and game-state-dependent moves, can still depend on blockers or game state.

Custom piece 1 (O) movement

N

Custom piece 2 (S) movement

N

Custom piece 3 (V) movement

R

Custom piece 4 (W) movement

R

Custom piece 5 (T) movement

Q

Custom piece 6 (U) movement

Q

Custom piece 7 (X) movement

B

Custom piece 8 (P) movement

mfWcfFinD

move capture move or capture initial only hopper target

Fairy-Stockfish rules

[twister-chess]

#pychessPieces = p,n,o,s,+n,+o,+s,b,x,+b,+x,r,v,w,+r,+v,+w,q,t,u,+q,+t,+u,k
startFen = rnbqkxsr/pppppppp/8/8/8/8/PPPPPPPP/ROBQKXNR w kqKQ
# Pawn
customPiece8 = p:mfWcfFinD

# Colored knights
knight = n
customPiece1 = o:N
customPiece2 = s:N
mobilityRegionWhiteKnight = a1 d1 e1 h1 c2 g2 b3 f3 a4 d4 e4 h4 a5 d5 e5 h5 c6 g6 b7 f7 a8 d8 e8 h8
mobilityRegionBlackKnight = a1 d1 e1 h1 c2 g2 b3 f3 a4 d4 e4 h4 a5 d5 e5 h5 c6 g6 b7 f7 a8 d8 e8 h8
mobilityRegionWhiteCustomPiece1 = b1 f1 a2 d2 e2 h2 c3 g3 b4 f4 b5 f5 a6 d6 e6 h6 c7 g7 b8 f8
mobilityRegionBlackCustomPiece1 = b1 f1 a2 d2 e2 h2 c3 g3 b4 f4 b5 f5 a6 d6 e6 h6 c7 g7 b8 f8
mobilityRegionWhiteCustomPiece2 = c1 g1 b2 f2 a3 d3 e3 h3 c4 g4 c5 g5 b6 f6 a7 d7 e7 h7 c8 g8
mobilityRegionBlackCustomPiece2 = c1 g1 b2 f2 a3 d3 e3 h3 c4 g4 c5 g5 b6 f6 a7 d7 e7 h7 c8 g8

# Bishop
bishop = b
customPiece7 = x:B
mobilityRegionWhiteBishop = c1 g1 b2 f2 a3 d3 e3 h3 c4 g4 c5 g5 b6 f6 a7 d7 e7 h7 c8 g8
mobilityRegionBlackBishop = c1 g1 b2 f2 a3 d3 e3 h3 c4 g4 c5 g5 b6 f6 a7 d7 e7 h7 c8 g8
mobilityRegionWhiteCustomPiece7 = b1 f1 a2 d2 e2 h2 c3 g3 b4 f4 b5 f5 a6 d6 e6 h6 c7 g7 b8 f8
mobilityRegionBlackCustomPiece7 = b1 f1 a2 d2 e2 h2 c3 g3 b4 f4 b5 f5 a6 d6 e6 h6 c7 g7 b8 f8

# Colored rooks

rook = r
customPiece3 = v:R
customPiece4 = w:R
mobilityRegionWhiteRook = a1 d1 e1 h1 c2 g2 b3 f3 a4 d4 e4 h4 a5 d5 e5 h5 c6 g6 b7 f7 a8 d8 e8 h8
mobilityRegionBlackRook = a1 d1 e1 h1 c2 g2 b3 f3 a4 d4 e4 h4 a5 d5 e5 h5 c6 g6 b7 f7 a8 d8 e8 h8
mobilityRegionWhiteCustomPiece3 = b1 f1 a2 d2 e2 h2 c3 g3 b4 f4 b5 f5 a6 d6 e6 h6 c7 g7 b8 f8
mobilityRegionBlackCustomPiece3 = b1 f1 a2 d2 e2 h2 c3 g3 b4 f4 b5 f5 a6 d6 e6 h6 c7 g7 b8 f8
mobilityRegionWhiteCustomPiece4 = c1 g1 b2 f2 a3 d3 e3 h3 c4 g4 c5 g5 b6 f6 a7 d7 e7 h7 c8 g8
mobilityRegionBlackCustomPiece4 = c1 g1 b2 f2 a3 d3 e3 h3 c4 g4 c5 g5 b6 f6 a7 d7 e7 h7 c8 g8

# Colored queens

queen = q
customPiece5 = t:Q
customPiece6 = u:Q
mobilityRegionWhiteQueen = a1 d1 e1 h1 c2 g2 b3 f3 a4 d4 e4 h4 a5 d5 e5 h5 c6 g6 b7 f7 a8 d8 e8 h8
mobilityRegionBlackQueen = a1 d1 e1 h1 c2 g2 b3 f3 a4 d4 e4 h4 a5 d5 e5 h5 c6 g6 b7 f7 a8 d8 e8 h8
mobilityRegionWhiteCustomPiece5 = b1 f1 a2 d2 e2 h2 c3 g3 b4 f4 b5 f5 a6 d6 e6 h6 c7 g7 b8 f8
mobilityRegionBlackCustomPiece5 = b1 f1 a2 d2 e2 h2 c3 g3 b4 f4 b5 f5 a6 d6 e6 h6 c7 g7 b8 f8
mobilityRegionWhiteCustomPiece6 = c1 g1 b2 f2 a3 d3 e3 h3 c4 g4 c5 g5 b6 f6 a7 d7 e7 h7 c8 g8
mobilityRegionBlackCustomPiece6 = c1 g1 b2 f2 a3 d3 e3 h3 c4 g4 c5 g5 b6 f6 a7 d7 e7 h7 c8 g8

# King
king = k

# Promotions
promotionPawnTypes = *
promotionRegionWhite = *1 *2 *3 *4 *5 *6 *7 *8
promotionRegionBlack = *1 *2 *3 *4 *5 *6 *7 *8
promotionPieceTypes = -
promotedPieceType = n:o o:s s:n r:v v:w w:r q:t t:u u:q b:x x:b
mandatoryPiecePromotion = true
pieceDemotion = true