RoadRunner#

../../../_images/road_runner.gif

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/RoadRunner-v5")

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

Description#

You control the Road Runner(TM) in a race; you can control the direction to run in and times to jumps.The goal is to outrun Wile E. Coyote(TM) while avoiding the hazards of the desert.The game begins with three lives. You lose a life when the coyote catches you, picks you up in a rocket, or shoots you with a cannon. You also lose a life when a truck hits you, you hit a land mine, you fall off a cliff,or you get hit by a falling rock.You score points (i.e. rewards) by eating seeds along the road, eating steel shot, and destroying the coyote.

For a more detailed documentation, see the AtariAge page

Actions#

RoadRunner has the action space Discrete(18) with the table below lists the meaning of each action’s meanings. As RoadRunner 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

Value

Meaning

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)

Rewards#

Score points are your only reward. You get score points each time you:

actions

points

eat a pile of birdseed

100

eat steel shot

100

get the coyote hit by a mine (cannonball, rock, etc.)

200

get the coyote hit by a truck

1000

For a more detailed documentation, see the AtariAge page.

Variants#

RoadRunner 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=

RoadRunner-v0

"rgb"

(2, 5)

0.25

RoadRunner-ram-v0

"ram"

(2, 5)

0.25

RoadRunner-ramDeterministic-v0

"ram"

4

0.25

RoadRunner-ramNoFrameskip-v0

"ram"

1

0.25

RoadRunnerDeterministic-v0

"rgb"

4

0.25

RoadRunnerNoFrameskip-v0

"rgb"

1

0.25

RoadRunner-v4

"rgb"

(2, 5)

0.0

RoadRunner-ram-v4

"ram"

(2, 5)

0.0

RoadRunner-ramDeterministic-v4

"ram"

4

0.0

RoadRunner-ramNoFrameskip-v4

"ram"

1

0.0

RoadRunnerDeterministic-v4

"rgb"

4

0.0

RoadRunnerNoFrameskip-v4

"rgb"

1

0.0

ALE/RoadRunner-v5

"rgb"

4

0.25

ALE/RoadRunner-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