Rustic Alpha 3.0.0 (2021, Unknown)

  • New features:
    • Killer Moves
    • Principal Variation Search (PVS)
  • Changes:
    • Switch versioning scheme to SemVer. Versions are going to be in the form "a.b.c" from now on, with the following meaning:
      • Increment a: A new strength-gaining feature was added.
      • Increment b: A bug was fixed that gained strength.
      • Increment c: A feature was added or a bug was fixed that did not gain stregnth. It is not necessary to test this version for a rating change.
  • Misc:
    • Updated crossbeam-channel to version 0.5.1
    • A Makefile was added, so Rustic can be built using "GNU Make". When typing "make" (or "gmake" in MacOS), the Makefile will build all Rustic versions for the platform it's being compiled on.
    • Re-add showing the size of the TT and number of threads in About.
    • Fairly large update of the book on

Rustic Alpha 2 (2021, March 17)

CCRL Blitz rating: +/- 1815 Elo

  • New Features:
    • Transposition table for search and perft.
    • Ordering on transposition table move.
    • Set TT size through --hash option or UCI parameter.
  • Improvement:
    • Move check extension higher up in the search routine, to prevent quiescence search while in check.
  • Changes:
    • seldepth: report max ply reached during the search, instead of selective depth at last completed iteration.
    • Count all nodes visited, instead of only nodes which generated moves.
    • Change random number generator from SmallRng to ChaChaRng for reproducible behavior between platforms/OS's/architectures/versions.
  • Cleanup
    • Change Root PV handling to remove redundant code.
    • Miscellaneous small renames, refactors, and cleanups.
    • Add rand_chacha and remove SmallRng number generators.
    • Update Rand library to 0.8.3.

Rustic Alpha 1.1 (2021, March 15)

This is a bugfix release. Alpha 1 lost all of its games on time forfeit when playing in MoveTime mode (for example, when playing seconds/move).


  • Do not exceed alotted time in MoveTime mode.

Rustic Alpha 1 (2021, January 24)

This is the initial release.

CCRL Blitz rating: +/- 1677 Elo

Below are the features included in this version.

  • Engine:
    • Bitboard board representation
    • Magic bitboard move generator
    • UCI-protocol
  • Search
    • Alpha/Beta search
    • Quiescence search
    • MVV-LVA move ordering
    • Check extension
  • Evaluation
    • Material counting
    • Piece-Square Tables