Mammoth is a program for playing chess variants. A chess variant is a game related to chess, which may differ from orthodox chess in various ways: unusual board (e.g. 8x10, 9x9 etc.), unusual pieces or piece placement etc. Mammoth supports several such variants, including Capablanca chess, Grand chess, Courier chess and many others (more than 30 variants are supported). Explanations about the rules are included in the program, see the help menu and tooltips.

The AI is based on a minimax algorithm with usual pruning heuristics. The evaluation function takes into account material (with an automated estimation of the value of the pieces based on their average mobility) together with a few positional factors such as pawn structure, king safety, piece mobility and control of the center. Mammoth can also play orthodox (standard) chess, but it is very far from being competitive with state-of-the-art chess engines (such as, e.g., Leela or Stockfish).

Compared to its elder brother Rabbit, Mammoth enjoys many additional features: clocks, analysis mode, support for opening trees etc.


An MSI installer for Mammoth (preliminary version) is available here. Mammoth is only available on windows.



Mammoth has been developed for fun and is offered for free. But those who are willing to pay can make a donation to any association for protection of animals.


Mammoth is still under development and may contain bugs. Software downloaded from this webpage is provided 'as is' without warranty of any kind, either expressed or implied.