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Gymnasium/docs/environments/atari/pitfall2.md

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Pitfall2

Pitfall2

:width: 120px
:name: Pitfall2

This environment is part of the Atari environments. Please read that page first for general information.

Action Space Discrete(18)
Observation Shape (210, 160, 3)
Observation High 255
Observation Low 0
Import gymnasium.make("ALE/Pitfall2-v5")

For more Pitfall2 variants with different observation and action spaces, see the variants section.

Description

Pitfall2 is missing description documentation. If you are interested in writing up a description, please create an issue or PR with the information on the Gymnasium github.

Actions

Pitfall2 has the action space Discrete(18) with the table below lists the meaning of each action's meanings. As Pitfall2 uses the full set of actions then specifying full_action_space=True will not modify the action space of the environment if passed to gymnasium.make.

Value Meaning
0 NOOP
1 FIRE
2 UP
3 RIGHT
4 LEFT
5 DOWN
6 UPRIGHT
7 UPLEFT
8 DOWNRIGHT
9 DOWNLEFT
10 UPFIRE
11 RIGHTFIRE
12 LEFTFIRE
13 DOWNFIRE
14 UPRIGHTFIRE
15 UPLEFTFIRE
16 DOWNRIGHTFIRE
17 DOWNLEFTFIRE

Observations

Atari environment have two possible observation types, the observation space is listed below. See variants section for the type of observation used by each environment id.

  • obs_type="rgb" -> observation_space=Box(0, 255, (210, 160, 3), np.uint8)
  • obs_type="ram" -> observation_space=Box(0, 255, (128,), np.uint8)

Additionally, obs_type="grayscale" cause the environment return a grayscale version of the rgb array for observations with the observation space being Box(0, 255, (210, 160), np.uint8)

Variants

Pitfall2 has the following variants of the environment id which have the following differences in observation, the number of frame-skips and the repeat action probability.

Env-id obs_type= frameskip= repeat_action_probability=
ALE/Pitfall2-v5 "rgb" 4 0.25
ALE/Pitfall2-ram-v5 "ram" 4 0.25

Difficulty and modes

It is possible to specify various flavors of the environment via the keyword arguments difficulty and mode. A flavor is a combination of a game mode and a difficulty setting. The table below lists the possible difficulty and mode values along with the default values.

Available Modes Default Mode Available Difficulties Default Difficulty
[0] 0 [0] 0

Version History

A thorough discussion of the intricate differences between the versions and configurations can be found in the general article on Atari environments.

  • v5: Stickiness was added back and stochastic frameskipping was removed. The environments are now in the "ALE" namespace.
  • v4: Stickiness of actions was removed
  • v0: Initial versions release