Answers.Body: <p>As mentioned by others, this move is perfectly legal (unless it puts your own king in check) and is called <strong><a href="https://en.wikipedia.org/wiki/Discovered_attack" rel="noreferrer">discovered check</a></strong> or  more generally <strong>discovered attack</strong> (if the attacked piece is not the king). </p>
  
  <p>This is usually a deadly tactic because the piece moved effectively gets to move twice while the opponent has to deal with the check from the other piece. This allows you to:</p>
  
  <ol>
  <li>The moved piece can move to a square where it attacks a stronger piece which it will capture in the next move. (Bh7+ in the example below). The attacked piece cannot escape because the king is in check.</li>
  <li>The moved piece can capture anything directly without being recaptured. (Bxc6+ in the example below).</li>
  </ol>
  
  <p>Take a look at the following example:</p>
  
  <pre><code>[FEN "6q1/1p6/2p5/4k3/3pB3/6P1/5P1P/4R1K1 w - - 0 1"]
  
  1. Bh7+ {Black has to deal with the check and cannot capture this bishop with the queen} (1. Bxc6+ {Even though this pawn is protected by the pawn on b7, black has to deal with the check and cannot capture the bishop} Kd6 2. Bxb7 {White won two pawns}) Kd6 2. Bxg8
  </code></pre>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2017-03-02T10:17:53.680Z
Answers.LastActivityDate: 2017-03-02T10:17:53.680Z
Answers.UserDisplayName: user1583209
Answers.Body: <p>For USCF rules, there is no such rule as long as the piece you are moving does not expose your king to check in the process.</p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2015-05-15T03:04:07.047Z
Answers.LastActivityDate: 2015-05-15T03:04:07.047Z
Answers.UserDisplayName: Peter Birdsall
Answers.Body: <p>It's perfectly accurate to say that there is no such rule in the Laws of Chess.  Also, if your queen, your rook and his king are in a row his king is already in check, so his last move must have been illegal.</p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2016-03-08T14:08:29.593Z
Answers.Text: I think the OP means they are on the same diagonal, and he is describing *discovered check*.
Answers.UserDisplayName: Dag Oskar Madsen
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2016-03-08T13:57:05.680Z
Answers.LastActivityDate: 2016-03-08T13:57:05.680Z
Answers.UserDisplayName: Titus Weekes
Answers.Body: <p>You can move your other piece to make your queen attack the king in a normal position such as:</p>
  
  <pre><code>4r3/8/8/2QB1k2/p5q1/3K4/8/8 w - - 0 1
  
  1.Bf3+**[Discovered-Check]
  (1.Be4+**[Double-check])
  </code></pre>
  
  <hr>
  
  <p>But you are forbidden to do so if the piece you move will put your own king in check, such as: </p>
  
  <pre><code>3r4/8/8/2QB1k2/p5q1/3K4/8/8 w - - 0 1
  
  1.Bf3**[illegal-move] 
  </code></pre>
  
  <p>Here both Be4 and Bf3 are illegal because the rook on d8 will be attacking your King.</p>
  
  <p>So to conclude, there is no standard rule avoiding you to play discovered check except when the move puts your own king in check.</p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2015-05-04T08:51:33.717Z
Answers.LastActivityDate: 2015-05-04T10:58:28.703Z
Answers.LastEditDate: 2015-05-04T10:58:28.703Z
Answers.UserDisplayName: Pavan Nadig
Body: <p>I was recently told that you may not move a piece out of the way of a second piece to allow the second piece to put the other player in check.</p>
  <p>For example,</p>
  <ul>
  <li>I have my queen and rook lined up on a diagonal with my opponent's king.</li>
  <li>I move my rook, opening the path for my queen to their king putting it in check.</li>
  </ul>
  <p>According to my opponent, you aren't allowed to do this. You have to actively move the queen into a check position.</p>
  <p>Is this a standard rule?</p>
  
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2015-05-04T02:39:12.497Z
Comments.Text: There is no such rule. Giving check by moving a piece out of the way is called "[discovered check](https://www.uschess.org/content/view/8757/492)". If the piece moving out of the way **also** gives check, it's called "double check".
Comments.UserDisplayName: bof
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2015-05-04T16:17:20.153Z
Comments.Text: @bof I wish you had made this an answer.
Comments.UserDisplayName: dfan
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-04-29T18:00:36.197Z
Comments.Text: No.  Whoever told you about this "rule" has no idea what they are talking about.
Comments.UserDisplayName: Qudit
Tags: <rules><checkmate><check><discovered-check>
Title: Moving a piece out of the way to check
ThreadText: # Moving a piece out of the way to check
  
  (Asked by: username_0 on 2015-05-04)
  
  I was recently told that you may not move a piece out of the way of a second piece to allow the second piece to put the other player in check.
  
  For example,
  
  * I have my queen and rook lined up on a diagonal with my opponent's king.
  * I move my rook, opening the path for my queen to their king putting it in check.
  
  According to my opponent, you aren't allowed to do this. You have to actively move the queen into a check position.
  
  Is this a standard rule?
  
  **Tags:** rules, checkmate, check, discovered-check
  
  > **Comments:**
  > **username_1**: There is no such rule. Giving check by moving a piece out of the way is called "[discovered check](https://www.uschess.org/content/view/8757/492)". If the piece moving out of the way **also** gives check, it's called "double check".  
  > **username_2**: @username_1 I wish you had made this an answer.  
  > **username_3**: No.  Whoever told you about this "rule" has no idea what they are talking about.  
  
  ---
  
  ## 4 answers
  
  ### Answer by username_8 on 2015-05-04. Score: 18 | Accepted answer
  
  You can move your other piece to make your queen attack the king in a normal position such as:
  
  ```
  4r3/8/8/2QB1k2/p5q1/3K4/8/8 w - - 0 1
  
  1.Bf3+**[Discovered-Check]
  (1.Be4+**[Double-check])
  
  ```
  
  ---
  
  But you are forbidden to do so if the piece you move will put your own king in check, such as:
  
  ```
  3r4/8/8/2QB1k2/p5q1/3K4/8/8 w - - 0 1
  
  1.Bf3**[illegal-move] 
  
  ```
  
  Here both Be4 and Bf3 are illegal because the rook on d8 will be attacking your King.
  
  So to conclude, there is no standard rule avoiding you to play discovered check except when the move puts your own king in check.
  
  
  ---
  
  ### Answer by username_4 on 2017-03-02. Score: 7
  
  As mentioned by others, this move is perfectly legal (unless it puts your own king in check) and is called **[discovered check](https://en.wikipedia.org/wiki/Discovered_attack)** or more generally **discovered attack** (if the attacked piece is not the king).
  
  This is usually a deadly tactic because the piece moved effectively gets to move twice while the opponent has to deal with the check from the other piece. This allows you to:
  
  1. The moved piece can move to a square where it attacks a stronger piece which it will capture in the next move. (Bh7+ in the example below). The attacked piece cannot escape because the king is in check.
  2. The moved piece can capture anything directly without being recaptured. (Bxc6+ in the example below).
  
  Take a look at the following example:
  
  ```
  [FEN "6q1/1p6/2p5/4k3/3pB3/6P1/5P1P/4R1K1 w - - 0 1"]
  
  1. Bh7+ {Black has to deal with the check and cannot capture this bishop with the queen} (1. Bxc6+ {Even though this pawn is protected by the pawn on b7, black has to deal with the check and cannot capture the bishop} Kd6 2. Bxb7 {White won two pawns}) Kd6 2. Bxg8
  
  ```
  
  
  ---
  
  ### Answer by username_5 on 2015-05-15. Score: 2
  
  For USCF rules, there is no such rule as long as the piece you are moving does not expose your king to check in the process.
  
  
  ---
  
  ### Answer by username_6 on 2016-03-08. Score: 0
  
  It's perfectly accurate to say that there is no such rule in the Laws of Chess. Also, if your queen, your rook and his king are in a row his king is already in check, so his last move must have been illegal.
  
  > **Comments:**
  > **username_7**: I think the OP means they are on the same diagonal, and he is describing *discovered check*.  
  
  ---
  
  