Answers.Body: <p>I found that we shouldn't eliminate those actions, because <code>RIGHTFIRE</code> and <code>LEFTFIRE</code> do <code>RIGHT</code> + <code>FIRE</code> and <code>LEFT</code> + <code>FIRE</code>, respectively. So they are different actions. I post this just to clarify in case someone faces the same doubt.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-03-23T15:04:42.993Z
Answers.LastActivityDate: 2020-12-27T13:57:19.517Z
Answers.LastEditDate: 2020-12-27T13:57:19.517Z
Answers.UserDisplayName: JCP
Body: <p>I'm trying to replicate the DeepMind DQN paper. I'm using OpenAI's Gym. I'm trying to get a decent score with Space Invaders (using <code>SpaceInvaders-v4</code> environment). I checked the actions available with <code>env.unwrapped.get_action_meanings()</code>, and I get this:</p>
  <pre><code>['NOOP', 'FIRE', 'RIGHT', 'LEFT', 'RIGHTFIRE', 'LEFTFIRE']
  </code></pre>
  <p>Checking the number of actions with <code>env.action_space.n</code> gives me a number of 6 actions.</p>
  <p>The <code>RIGHTFIRE</code> and <code>LEFTFIRE</code> actions, I suppose, aren't used, given that they <em>seem</em> to do the same as <code>LEFT</code> and <code>RIGHT</code>, am I right?</p>
  <p>If so, restricting the action size to the 4 first actions would improve my learning?</p>
  
Tags: <reinforcement-learning><dqn><deep-rl><gym><action-spaces>
Title: Should I ignore the actions RIGHTFIRE and LEFTFIRE in the SpaceInvaders environment?
UserDisplayName: JCP
ThreadText: # Should I ignore the actions RIGHTFIRE and LEFTFIRE in the SpaceInvaders environment?
  
  (Asked by: username_0 on 2019-03-13)
  
  I'm trying to replicate the DeepMind DQN paper. I'm using OpenAI's Gym. I'm trying to get a decent score with Space Invaders (using SpaceInvaders-v4 environment). I checked the actions available with env.unwrapped.get_action_meanings(), and I get this:
  ['NOOP', 'FIRE', 'RIGHT', 'LEFT', 'RIGHTFIRE', 'LEFTFIRE']
  
  Checking the number of actions with env.action_space.n gives me a number of 6 actions.
  The RIGHTFIRE and LEFTFIRE actions, I suppose, aren't used, given that they seem to do the same as LEFT and RIGHT, am I right?
  If so, restricting the action size to the 4 first actions would improve my learning?
  
  **Tags:** reinforcement-learning, dqn, deep-rl, gym, action-spaces
  
  ---
  
  ## 1 answers
  
  ### Answer by username_0 on 2019-03-23. Score: 0 | Accepted answer
  
  I found that we shouldn't eliminate those actions, because `RIGHTFIRE` and `LEFTFIRE` do `RIGHT` + `FIRE` and `LEFT` + `FIRE`, respectively. So they are different actions. I post this just to clarify in case someone faces the same doubt.
  
  
  ---
  
  