Castling rights refers to whether a player is allowed to castle in the rest of the game. There are rules whereby you cannot castle if your King has moved at any time in the game, even if it moves back to its home square. If the King has moved, you have lost the “right to castle” for the rest of the game. This loss of “castling right” refers to castling on both sides of the board, if the King moves. So don’t move your King if you can help it, but try to make your opponent move their King!
Prior moves by the Rook also lose the right to castle with that Rook. However, you can still castle with the other side Rook if it hasn’t moved previously. And also that assumes that the King hasn’t already moved, which disallows castling rights on both sides.
Note that there are other moves with prevent castling at the current move, but don’t permanently lose the right to castle. If you are in check, you cannot “castle out of check” but you will be allowed to castle later in the game. That is, assuming you don’t move the King! You can still castle later if you block the check with another piece or capture the checking piece (but not with the King).
Related Chess Rules Topics
Read more about these related chess rules, chess puzzles, and other chess tactics and strategies: