Answers.Body: <p>By the FIDE <a href="http://www.fide.com/component/handbook/?id=124&amp;view=article" rel="nofollow noreferrer">Laws of Chess</a>, article 7.4:</p>
  <blockquote>
  <p>7.4</p>
  </blockquote>
  <blockquote>
  <ul>
  <li>a. If during a game it is found that an illegal move, including
  failing to meet the requirements of the promotion of a pawn or
  capturing the opponent’s king, has been completed, the position
  immediately before the irregularity shall be reinstated. If the
  position immediately before the irregularity cannot be determined the
  game shall continue from the last identifiable position prior to the
  irregularity. The clocks shall be adjusted according to Article 6.13.
  The Articles 4.3 and 4.6 apply to the move replacing the illegal
  move. The game shall then continue from this re-instated position.</li>
  </ul>
  </blockquote>
  <blockquote>
  <ul>
  <li>b. After the action taken under Article 7.4.a, for the first two
  illegal moves by a player the arbiter shall give two minutes extra
  time to his opponent in each instance; for a third illegal move by
  the same player, the arbiter shall declare the game lost by this
  player. However, the game is drawn if the position is such that the
  opponent cannot checkmate the player’s king by any possible series of
  legal moves.</li>
  </ul>
  </blockquote>
  <p>That is, on the two first illegal moves of your opponent, you gain time on your clock (two minutes, which likely does nothing), but on the third illegal move of your opponent, they lose the game (unless it was already impossible for them to lose it).</p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2014-09-24T01:38:21.507Z
Answers.Text: As a corollary: Stop the clock, get the arbiter. *Always* get the arbiter in the case of a dispute.
Answers.UserDisplayName: kahen
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2014-09-24T05:47:23.070Z
Answers.Text: And of course, those rules are only valid for long time controls (standard), for short time controls other rules apply, see the appendixes.
Answers.UserDisplayName: Pablo S. Ocal
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2014-10-02T09:02:58.387Z
Answers.Text: It is important to note that touch-move rule still stands, as explained in Article 4.3, which is referred to in the quote. (I've won at least one game when my opponent didn't notice he is in check, moved his rook, and was so unlucky that the rook had one legal move to an unprotected square blocking the check.)
Answers.UserDisplayName: JiK
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2021-02-01T02:25:04.983Z
Answers.Text: "but on the third move you lose the game (unless it was already impossible for you to win it)." Shouldn't that be "unless it was impossible for you to lose it"?
Answers.UserDisplayName: Acccumulation
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2014-09-23T22:42:55.057Z
Answers.LastActivityDate: 2021-02-03T00:08:04.690Z
Answers.LastEditDate: 2021-02-03T00:08:04.690Z
Answers.UserDisplayName: Pablo S. Ocal
Answers.Body: <p>When it comes to Blitz games (5 minutes or 3 minutes + 2 seconds) first illegal move loses the game on the spot. Other solutions (like adding 2 minutes) would lead to total confusion.</p>
  
  <p>Keep in mind, after your oponent has made an illegal move, you are obliged to:</p>
  
  <ul>
  <li>stop the clock</li>
  <li>call the arbiter</li>
  <li>explain what happened</li>
  </ul>
  
  <p>(btw, you must have time on your clock, if you are already at 0:00 then you can't do anything)</p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2014-09-24T18:29:53.060Z
Answers.LastActivityDate: 2014-09-24T18:41:25.493Z
Answers.LastEditDate: 2014-09-24T18:41:25.493Z
Answers.UserDisplayName: Pijotrek
Body: <p>I heard that they lose some time or that they lose the game. I'm not sure what happens.</p>
  
Tags: <rules><learning><illegal-move>
Title: What are the official rules if your opponent makes an illegal move?
ThreadText: # What are the official rules if your opponent makes an illegal move?
  
  (Asked by: username_0 on 2014-09-23)
  
  I heard that they lose some time or that they lose the game. I'm not sure what happens.
  
  **Tags:** rules, learning, illegal-move
  
  
  ---
  
  ## 2 answers
  
  ### Answer by username_1 on 2014-09-23. Score: 6
  
  By the FIDE [Laws of Chess](http://www.fide.com/component/handbook/?id=124&view=article), article 7.4:
  
  > 7.4
  
  > * a. If during a game it is found that an illegal move, including
  >   failing to meet the requirements of the promotion of a pawn or
  >   capturing the opponent’s king, has been completed, the position
  >   immediately before the irregularity shall be reinstated. If the
  >   position immediately before the irregularity cannot be determined the
  >   game shall continue from the last identifiable position prior to the
  >   irregularity. The clocks shall be adjusted according to Article 6.13.
  >   The Articles 4.3 and 4.6 apply to the move replacing the illegal
  >   move. The game shall then continue from this re-instated position.
  
  > * b. After the action taken under Article 7.4.a, for the first two
  >   illegal moves by a player the arbiter shall give two minutes extra
  >   time to his opponent in each instance; for a third illegal move by
  >   the same player, the arbiter shall declare the game lost by this
  >   player. However, the game is drawn if the position is such that the
  >   opponent cannot checkmate the player’s king by any possible series of
  >   legal moves.
  
  That is, on the two first illegal moves of your opponent, you gain time on your clock (two minutes, which likely does nothing), but on the third illegal move of your opponent, they lose the game (unless it was already impossible for them to lose it).
  
  > **Comments:**
  > **username_2**: As a corollary: Stop the clock, get the arbiter. *Always* get the arbiter in the case of a dispute.  
  > **username_1**: And of course, those rules are only valid for long time controls (standard), for short time controls other rules apply, see the appendixes.  
  > **username_3**: It is important to note that touch-move rule still stands, as explained in Article 4.3, which is referred to in the quote. (I've won at least one game when my opponent didn't notice he is in check, moved his rook, and was so unlucky that the rook had one legal move to an unprotected square blocking the check.)  
  > **username_4**: "but on the third move you lose the game (unless it was already impossible for you to win it)." Shouldn't that be "unless it was impossible for you to lose it"?  
  
  ---
  
  ### Answer by username_5 on 2014-09-24. Score: 3
  
  When it comes to Blitz games (5 minutes or 3 minutes + 2 seconds) first illegal move loses the game on the spot. Other solutions (like adding 2 minutes) would lead to total confusion.
  
  Keep in mind, after your oponent has made an illegal move, you are obliged to:
  
  * stop the clock
  * call the arbiter
  * explain what happened
  
  (btw, you must have time on your clock, if you are already at 0:00 then you can't do anything)
  
  
  ---
  
  