Since Gym 0.9.6, the board games environment has been removed from the default package as they are not maintained by OpenAI [ref]. This article helps who would like to run their AI on Go or Hex in OpenAI Gym.

1. Locate the python Gym package folder. In my case, it is under ~/anaconda3/envs/openai-gym/lib/python3.5/site-packages/gym.

2. Download the Gym 0.9.5 source code which contains the board games environment.

3. Copy the board_game folder from 0.9.5 source code (under /gym-0.9.5/gym/envs/) to your local Gym package envrionment folder (my case is ~/anaconda3/envs/openai-gym/lib/python3.5/site-packages/gym/envs).

4. Add the following code into init.py (~/anaconda3/envs/openai-gym/lib/python3.5/site-packages/gym/envs/__init__.py). It will register those envs.

# Board games
# ----------------------------------------

register(
    id='Go9x9-v0',
    entry_point='gym.envs.board_game:GoEnv',
    kwargs={
        'player_color': 'black',
        'opponent': 'pachi:uct:_2400',
        'observation_type': 'image3c',
        'illegal_move_mode': 'lose',
        'board_size': 9,
    },
    # The pachi player seems not to be determistic given a fixed seed.
    # (Reproduce by running 'import gym; h = gym.make('Go9x9-v0'); h.seed(1); h.reset(); h.step(15); h.step(16); h.step(17)' a few times.)
    #
    # This is probably due to a computation time limit.
    nondeterministic=True,
)

register(
    id='Go19x19-v0',
    entry_point='gym.envs.board_game:GoEnv',
    kwargs={
        'player_color': 'black',
        'opponent': 'pachi:uct:_2400',
        'observation_type': 'image3c',
        'illegal_move_mode': 'lose',
        'board_size': 19,
    },
    nondeterministic=True,
)

register(
    id='Hex9x9-v0',
    entry_point='gym.envs.board_game:HexEnv',
    kwargs={
        'player_color': 'black',
        'opponent': 'random',
        'observation_type': 'numpy3c',
        'illegal_move_mode': 'lose',
        'board_size': 9,
    },
)

5. Install pachi-py via pip install pachi-py for go env.

Then it’s all set to use the board game environment.

All in all, Gym is built for testing reinforcement learning, and the reinforcement learning gains fames from the DeepMind AlphaGo. Personally, removing Go env from Gym is not a smart move for marketing.