Breakout#

../../../_images/breakout.gif

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

Action Space

Discrete(4)

Observation Shape

(210, 160, 3)

Observation High

255

Observation Low

0

Import

gymnasium.make("ALE/Breakout-v5")

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

Description#

Another famous Atari game. The dynamics are similar to pong: You move a paddle and hit the ball in a brick wall at the top of the screen. Your goal is to destroy the brick wall. You can try to break through the wall and let the ball wreak havoc on the other side, all on its own! You have five lives.

For a more detailed documentation, see the AtariAge page

Actions#

Breakout has the action space Discrete(4) with the table below lists the meaning of each action’s meanings. As Breakout uses a reduced set of actions for v0, v4 and v5 versions of the environment. To enable all 18 possible actions that can be performed on an Atari 2600, specify full_action_space=True during initialization or by passing full_action_space=True to gymnasium.make.

Value

Meaning

Value

Meaning

Value

Meaning

0

NOOP

1

FIRE

2

RIGHT

3

LEFT

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)

Rewards#

You score points by destroying bricks in the wall. The reward for destroying a brick depends on the color of the brick. For a more detailed documentation, see the AtariAge page.

Variants#

Breakout 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=

Breakout-v0

"rgb"

(2, 5)

0.25

Breakout-ram-v0

"ram"

(2, 5)

0.25

Breakout-ramDeterministic-v0

"ram"

4

0.25

Breakout-ramNoFrameskip-v0

"ram"

1

0.25

BreakoutDeterministic-v0

"rgb"

4

0.25

BreakoutNoFrameskip-v0

"rgb"

1

0.25

Breakout-v4

"rgb"

(2, 5)

0.0

Breakout-ram-v4

"ram"

(2, 5)

0.0

Breakout-ramDeterministic-v4

"ram"

4

0.0

Breakout-ramNoFrameskip-v4

"ram"

1

0.0

BreakoutDeterministic-v4

"rgb"

4

0.0

BreakoutNoFrameskip-v4

"rgb"

1

0.0

ALE/Breakout-v5

"rgb"

4

0.25

ALE/Breakout-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, 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44]

0

[0, 1]

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