RL-related Tutorial

This page contains a general tutorial on how to use dgisim for RL.

Note

Linear game simulation environment is provided, but if you want to apply Monte-Carlo Tree Search or other non-linear methods, you need to implement your own game simulation environment (for now).

GameState is perfectly suitable for efficient MCTS, please refer to documentations on GameState for more details.

Linear Game Environment

Currently LinearEnv is provided for RL environment for linear simulation process.

A simple example of using LinearEnv is as follows:

from dgisim import LinearEnv

env = LinearEnv()
rl_net = ...  # your RL network

for _ in range(100):
    env.reset()
    game_state, encoded_state, reward, turn, done = env.view()

    while not done:
        action = rl_net(encoded_state)  # this is just an example, your network
                                        # doesn't have to directly generate an action
        game_state, encoded_state, reward, turn, done = env.step(action)

The default behaviour of LinearEnv is to generate a random game state at the beginning of each episode. You may also reset the environment with two specific decks for each player by calling .reset_with_decks(deck1, deck2).

Note

.reset() follows the last way of resetting the environment. If you want to reset the environment with random deck after calling .reset_with_decks(), you should call .reset_random().

Note

If you want to get the decks used by the players in the current episode, you need to call .extract_decks() on the initial game state right after resetting. (As the game progress, some information on the decks are lost, thus you may not get the complete decks by calling .extract_decks() on later game states.)

env.reset()
initial_game_state = env.full_view()
deck1, deck2 = initial_game_state.extract_decks()

LinearEnv.step() takes either a list of int as the encoded player action that might be an output of a NN, or a PlayerAction object. If the action failed to be decoded or is invalid in other ways, the same game state will be returned with a customizable penalty (default to -0.1).

The reward is:

• If Game Ends:

  • 1 if player 1 wins

  • 0 if draw

  • -1 if player 2 wins

• If Invalid Action:

  • -0.1 if player 1 makes an invalid action

  • 0.1 if player 2 makes an invalid action

• Otherwise:

  • 0

All the return values above can be customized by passing values to LinearEnv when initializing.

Game Encoding Details

A GameState object is encoded as a 1D vector of length 2778.

The encoding for a GameState object is ordered as follows:

• 4 ints for basic game information (game mode, game phase, round number, active player id)

• 839 ints for player 1 information (deck, hand, characters, statuses, summons, supports…)

• 839 ints for player 2 information

• 1000 ints for all pending effects to be executed (useful when facing death swap)

The encoding for a PlayerState object is ordered as follows:

• 4 ints for basic information (player phase, right for consecutive action…)

• 20 ints for dice

• 50 ints for hand cards (designed for 40 cards max for future expansion)

• 50 ints for deck cards

• 50 ints for publicly used cards (cards used that your opponent can see)

• 50 ints for publicly gained cards (cards gained that your opponent can see)

• 53 ints for initial deck (containing 3 characters and 30 cards)

• 414 ints for characters

• 70 ints for hidden statuses (whether plunge attack is available…)

• 70 ints for combat statuses (designed for 10 statuses max)

• 28 ints for summons

• 28 ints for supports

The encoding for a Character object is ordered as follows:

• 9 ints for basic information (character type, character element, weapon type…)

• 10 ints for elemental application / aura

• 28 ints for hidden statuses (empty for most characters, but a few need this)

• 91 ints for character statuses

The 1000 ints for pending effects can encoding a maximum of 40 effects, which is enough for most cases. (only 1 game state out of over 1,000,000 game states in hundreds of random plays can reach 23 pending effects)

Custom Encoding

If you want ot use your own way of encoding, you may instantialize your own EncodingPlan object and pass it to LinearEnv when initializing.

Please refer to the documentations on EncodingPlan for more details.