Community variant
Blunderful
If a blunder is possible, you must take it
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 inherits its base rules from `giveaway` and overrides the settings shown below.
Board and setup
Pieces and movement
- The piece set used on the board is: king (k), queen (q), rook (r), bishop (b), knight (n) and pawn (p).
Winning and losing
- An extinction rule is active: reaching 0 remaining piece(s) configured pieces causes a win for the side to move.
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.
K
move
capture
move or capture
initial only
hopper target
Fairy-Stockfish rules
[blunderful:giveaway]
# Force captures like Antichess so players are forced into bad trades
# Invert piece values so losing pieces is mathematically rewarded by the engine
pieceValueMg = p:1000 n:500 b:400 r:300 q:100 k:0
pieceValueEg = p:1000 n:500 b:400 r:300 q:100 k:0
extinctionValue = win