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---
title: Frostbite
---
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# Frostbite
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```{figure} ../../_static/videos/atari/frostbite.gif
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:width: 120px
:name: Frostbite
```
This environment is part of the < a href = '..' > Atari environments< / a > . Please read that page first for general information.
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| | |
|---|---|
| Action Space | Discrete(18) |
| Observation Shape | (210, 160, 3) |
| Observation High | 255 |
| Observation Low | 0 |
| Import | `gymnasium.make("ALE/Frostbite-v5")` |
For more Frostbite variants with different observation and action spaces, see the variants section.
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## Description
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In Frostbite, the player controls "Frostbite Bailey" who hops back and forth across across an Arctic river, changing the color of the ice blocks from white to blue. Each time he does so, a block is added to his igloo.
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For a more detailed documentation, see [the AtariAge page ](https://atariage.com/manual_html_page.php?SoftwareLabelID=199 )
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## Actions
Frostbite has the action space `Discrete(18)` with the table below lists the meaning of each action's meanings.
As Frostbite 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` |
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## Observations
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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.
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- `obs_type="rgb" -> observation_space=Box(0, 255, (210, 160, 3), np.uint8)`
- `obs_type="ram" -> observation_space=Box(0, 255, (128,), np.uint8)`
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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
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The exact reward dynamics depend on the environment and are usually documented in the game's manual. You can
find these manuals on [AtariAge ](https://atariage.com/manual_html_page.php?SoftwareLabelID=199 ).
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Atari environments are simulated via the Arcade Learning Environment (ALE) [[1]](#1 ).
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## Variants
Frostbite 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= |
|-------------------------------|-------------|--------------|------------------------------|
| Frostbite-v0 | `"rgb"` | `(2, 5)` | `0.25` |
| Frostbite-ram-v0 | `"ram"` | `(2, 5)` | `0.25` |
| Frostbite-ramDeterministic-v0 | `"ram"` | `4` | `0.25` |
| Frostbite-ramNoFrameskip-v0 | `"ram"` | `1` | `0.25` |
| FrostbiteDeterministic-v0 | `"rgb"` | `4` | `0.25` |
| FrostbiteNoFrameskip-v0 | `"rgb"` | `1` | `0.25` |
| Frostbite-v4 | `"rgb"` | `(2, 5)` | `0.0` |
| Frostbite-ram-v4 | `"ram"` | `(2, 5)` | `0.0` |
| Frostbite-ramDeterministic-v4 | `"ram"` | `4` | `0.0` |
| Frostbite-ramNoFrameskip-v4 | `"ram"` | `1` | `0.0` |
| FrostbiteDeterministic-v4 | `"rgb"` | `4` | `0.0` |
| FrostbiteNoFrameskip-v4 | `"rgb"` | `1` | `0.0` |
| ALE/Frostbite-v5 | `"rgb"` | `4` | `0.25` |
| ALE/Frostbite-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, 2]` | `0` | `[0]` | `0` |
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## Version History
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A thorough discussion of the intricate differences between the versions and configurations can be found in the general article on Atari environments.
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* 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
