Community variant

Butt Chess

https://github.com/SebLague/Chess-Challenge/issues/507 not cannon move is Queen + Zebra move

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: Supreme_Due
Visibility: public
Status: active

Generated rule overview

This variant inherits its base rules from `seirawan` and overrides the settings shown below.

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), Pawn (p) and Buttock (u).
Buttock (u) is a custom piece with Betza movement `QZ`.

Drops and hands

Pieces in hand can be dropped back onto the board. Droppable pieces are: Buttock (u).

Promotion

The pieces that can promote are: Pawn (p).
Promotion choices are both sides: Buttock (u), Queen (q), Bishop (b), Knight (n) and Rook (r).

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.

Buttock (U) movement

QZ

move capture move or capture initial only hopper target

Fairy-Stockfish rules

[buttchess:seirawan]
customPiece1 = u:QZ
startFen=rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR[Uu] w KQkq - 0 1
promotionPieceTypes=uqbnr