user9148: I am learning to play chess on my computer. I have learned approximately all the rules but one rule stays vague for me thus far.  
My questions are clear, though. I am putting them separated below with some little additions.

This is simple. How often can I castle? One time, two times, x
times or till the end? I know that it can be executed if a rook and
king are at their original places. 
If I am allowed to castle one time, does that imply that I can make it two times because number of rooks for each player is 2?


user8731: You can only castle once ever.  Part of the rule for castling is that you can only castle if your king has not moved.  So obviously you can never castle again, because castling entails moving your king.

user291: FIDE Laws of Chess:

3.8.b.1. The right to castle has been lost: a) if the king has already moved, or b) with a rook that has already moved.

Emphasis mine.

9148: <p>I am learning to play chess on my computer. I have learned approximately all the rules but one rule stays vague for me thus far.  </p>

<p>My questions are clear, though. I am putting them separated below with some little additions.</p>

<ol>
<li><p>This is simple. <strong>How often can I castle?</strong> One time, two times, x
times or till the end? I know that it can be executed if a rook and
king are at their original places. </p></li>
<li><p>If I am allowed to castle one time, does that imply that I can make it two times because number of rooks for each player is 2?</p></li>
</ol>
 8731: <p>You can only castle once ever.  Part of the rule for castling is that you can only castle if your king has not moved.  So obviously you can never castle again, because castling entails moving your king.</p>
 291: <p>FIDE Laws of Chess:</p>

<blockquote>
  <p>3.8.b.1. The right to castle has been lost: a) <strong>if the king has already moved</strong>, or b) with a rook that has already moved.</p>
</blockquote>

<p>Emphasis mine.</p>
