A library for chess move generation

chess, rust



A Rust library for chess move generation

Build Status crates.io docs.rs


  • Generate legal moves:

    use shakmaty::{Chess, Position};
    let pos = Chess::default();
    let legals = pos.legals();
    assert_eq!(legals.len(), 20);
  • Play moves:

    use shakmaty::{Square, Move, Role};
    // 1. e4
    let pos = pos.play(&Move::Normal {
        role: Role::Pawn,
        from: Square::E2,
        to: Square::E4,
        capture: None,
        promotion: None,
  • Detect game end conditions: pos.is_checkmate(), pos.is_stalemate(), pos.is_insufficient_material(), pos.outcome().

  • Read and write FENs, SANs and UCIs.

  • Supports standard chess, Chess960, Giveaway, Atomic, King Of The Hill, Three-Check, Crazyhouse, Racing Kings and Horde. Provides vocabulary to implement other variants.

  • Bitboards and compact fixed shift magic attack tables.

  • Probe Syzygy tablebases with shakmaty-syzygy.


Read the documentation


Simple perft of the initial position. No hashtables. i7-6850K CPU @ 3.60GHz.

perft 4 5
shakmaty 0.16.0 1.0 ms 24.1 ms
jordanbray/chess 3.1.1 0.8 ms 18.6 ms
Stockfish 8 (x86-64-bmi2) 4 ms 33 ms

It should be noted that Stockfish is not optimized for perft speed and also maintains additional data structures for evaluation. Newer versions of Stockfish put even less emphasis on this.


  • 0.16.2
    • Fix Racing King game end detection: Black cannot catch up if their own pieces block the goal.
    • Pawn drops in Crazyhouse are now considered zeroing.
  • 0.16.1
    • Fix (impossible) Crazyhouse insufficient material.
    • Fix (impossible) castling rights of exploded king in Atomic chess.
  • 0.16.0
    • Updated arrayvec to 0.5.x, which comes with significant performance improvements.
    • The default Giveaway position now has castling rights.
  • 0.15.3
    • Follow FICS rules in Atomic castling edge cases.
    • Use #[repr(align)] enum and reverse_bits() stabilized in Rust 1.37.
  • 0.15.2
    • In Horde chess, allow double pawn moves from the first rank.
    • Added {Square,Bitboard}::{flip_anti_diagonal,rotate_90,rotate_180,rotate_270}().
  • 0.15.1
    • FEN parser was expecting ~ before promoted pieces, but it should be after.
  • 0.15.0
    • Moved Position::from_setup() to a seperate new trait FromSetup.
    • Square and file/rank index calculations are now performed with u32 and i32, which is more performant than using the narrower types u8 and i8. The types are still #[repr(u8)].
    • Renamed Square::combine() to Square::with_rank_of().
    • Added Fen::from_setup().
    • Added FenOpts::scid() for Scid/Lichess compatible FEN formatting. Of course the parser also accepts these formats.
    • Added variant::Variant and VariantPosition for runtime selected chess variants. Limited to the built in variants.
    • Added {Material,MaterialSide}::is_empty().
  • 0.14.1
    • TryFrom now available on stable.
  • 0.14.0
    • SanPlus::from_move() no longer requires the move to be legal, which was an undocumented requirement. The new SanPlus::from_move_and_play_unchecked() is closest to the previous behavior.
    • Added San::disambiguate() and SanSuffix::from_position().
    • Implement TryFrom for various types on nightly.
    • Implement Add, AddAssign, Sub, SubAssign for Material and MaterialSide.
    • Added CastlingSide::from_{king|queen}_side().
    • Use u32 for depth argument of perft().
  • 0.13.1
    • Performance improvements on nightly (aligned Move enum).
  • 0.13.0
    • Replaced SanPlus::check and SanPlus::checkmate with san::Suffix enum.
    • Renamed {Rank,File}::rotate() to flip_diagonal().
    • Renamed Bitboard::flip() to toggle().
    • Added Square::coords().
    • Added Bitboard::flip_{vertical,horizontal,diagonal}().
    • Added Position::promotion_moves().
    • Derive Hash on Board, FenOpts, San, SanPlus, Suffix, Color, Role, Piece, RemainingChecks, CastlingSide, and Uci.
    • Minimum Rust version 1.31.0.
  • 0.12.0
    • Setup::halfmove_clock() is now Setup::halfmoves().
    • New conversions: f32::from(file), f64::from(rank).
    • Replaced Pockets and Pocket by more general Material and MaterialSide. Note that their Display and FromStr implementations differ.
    • Unified naming of error types.
  • 0.11.2
    • Fix Atomic insufficient material: KQN can mate.
  • 0.11.1
    • Fix Chess960 should not allow a-side castling over a blocking h-side rook.
  • 0.11.0
    • Outcome is now Copy.
    • Position::castling_uncovers_rank_attack() is no longer public.
  • 0.10.0
    • Added File, Rank. These are now returned by Square::{file, rank}. Square::from_coords(file, rank) takes the new types and is no longer fallible.
    • Bitboard is now IntoIterator instead of Iterator itself. Methods Bitboard::{first, last, count, is_empty} remain.
    • Bitboard::{add, flip, discard, with, without} are now generic over Into<Bitboard>. Alternative methods *_all have been removed.
    • Bitboard::relative_shift(color, shift: u8) now takes u32.
    • shakmaty::CarryRippler is now shakmaty::bitboard::CarryRippler.
    • Add new methods: Bitboard::{pop_front, pop_back, is_disjoint, is_subset, is_superset}.
    • Add Position::has_insufficient_material(color).
  • 0.9.0
    • Remove uci, chess960_uci, san and san_plus that were deprecated in 0.8.1.
    • Renamed *::from_bytes() to *::from_ascii().
    • Take small copy types by value: Piece::char(), CastlingSide::*.
    • Added Castles::has(color, side).
    • fen::{board_fen, epd, fen} are now shortcuts for formatting with default options.
    • Minimum rust version 1.27.0 (i128 conversions again, fused iterators again, Option::filter(), dyn Trait).
    • Eliminate many uses of unsafe, including TrustedLen impls, at minor cost.
  • 0.8.1
    • Make Role discriminants public.
    • Put San, SanPlus and Uci constructors on San, SanPlus and Uci respectively.
  • 0.8.0
    • Revert fused iterators and u128. Minimum Rust version back to 1.23.0.
    • Changed Role discriminants. Now starting with Pawn = 1.
    • Performance improvements (~12% faster perft).
    • Switch benchmarks to criterion.rs.
  • 0.7.2
    • Add Outcome.winner().
  • 0.7.1
    • Minimum Rust version 1.26.0 (fused iterators, u128 conversions).
  • 0.7.0
    • Reintroduce the remaining Lichess variants: Crazyhouse, KingOfTheHill, ThreeCheck, Horde, RacingKings.
    • Expose Position.castles() and replace Position.is_chess960() with Position.castles().is_chess960().
    • Fix insufficient material: KNvK was not given as drawn due to a typo.
    • Fix insufficient material in Atomic: Two knights of different colors are not safe.
    • Let Pockets.count() and Pocket.count() return usize.
  • 0.6.7
    • Giveaway starting position should have no castling rights.
  • 0.6.6
    • Fix missing king promotions in Giveaway.
  • 0.6.5
    • Validate color of missing king in atomic chess.
    • Clear move buffers before generating variant moves.
  • 0.6.4
    • Reintroduce Giveaway and Atomic chess variants.
  • 0.6.3
    • New method Move.is_zeroing().
  • 0.6.2
    • Make unit error types (InvalidSquareName, InvalidUci, InvalidSan) completely public.
    • Documentation, coding style and debugging tweaks.
  • 0.6.1
    • Expose attacks::bishop_mask and attacks::rook_mask.
    • Eliminate almost all unchecked indexing.
  • 0.6.0
    • Split impl From<Move> for Uci into uci() and chess960_uci().
    • Fix display of pawn drops.
    • Move generating methods clear the move buffer (and therefor no longer panic on too full buffers).
    • Added Position.is_chess960(), Bitboard.without_all(), Role.upper_char(), Board.stepper().
  • 0.5.1
    • Fix Uci::to_move() for en passant moves. Thanks zxqfl.
  • 0.5.0
    • Use u64 instead of usize for perft().
    • Export error type InvalidSquareName.
    • New methods: CastlingSide.is_{queen|king}_side(), San.matches(), Move.is_capture(), Move.is_promotion(), Move.castling_side(), Position.is_check().
    • Derive Ord and PartialOrd for Role.
    • Support running benchmarks on stable.
  • 0.4.2
    • Fix build error on beta due to the new nightly option_filter feature.
    • Fix unterminated code block in documentation.
  • 0.4.1
  • 0.4.0
    • Rename Color::from_bool() to Color::from_white(), add Color::from_black().
    • Add Move::role(), Move::is_en_passant() and Move::is_castle().
    • Add Position::en_passant_moves() and Position::capture_moves().
    • Implement BitXor<bool> for Color.
    • Implement FusedIterator and TrustedLen on Bitboard.
  • 0.3.0
    • Switch to #[repr(i8)] for Square. Implement all lossless integer conversions From<Square>.
    • Add Square::flip_horizontal(), flip_vertical() and flip_diagonal().
    • Efficiently implement CarryRippler::last() by @nvzqz.
    • Eliminate some unchecked indexing by @nvzqz.
    • Faster ASCII case conversions and tests by @nvzqz.
  • 0.2.0
    • Square is now a #[repr(u8)] enum.
    • Use bitflags for PositionError.
    • Rename RemainingChecks::subtract() to decrement().
    • Add Position::swap_turn().
  • 0.1.0
    • First release with support for stable Rust.


Shakmaty is licensed under the GPL-3.0 (or any later version at your option). See the COPYING file for the full license text.