Okay rules aficionados, here’s a scenario I would never have come up with if it hadn’t happened.
The gist of it is that White has just castled queenside. The resulting position has a White king on c1, a White rook on d1, and a Black knight on c2.
Black calls you over and asks, “I know the king cannot move through check, but can the rook?”
Variation 11H1 (director as witness to illegal move only) is being used.
How do you respond to the question in this bizarre scenario?
Assuming you meant white castled queenside. My response would be that you can castle if your rook is under attack, but you can’t castle out of check, so the castling was indeed illegal.
I do recall reading a story where a top GM, I think it was Korchnoi, was caught by surprise when his opponent got out of trouble by castling with a rook that was under attack.
Yes, queenside. Fixed.
You are answering more than was asked. I wasn’t asked whether castling was illegal in this position.
Per 21D1, you are permitted to and should answer questions about rules or procedures.
In this scenario, so as to not provide any more information than what you are being asked, I would probably answer the question with “(According to 8C1) A player may legally castle with a rook whose original square is under attack, a rook that crosses over a square under attack by an opponent’s piece or a rook that would end up occupying a square attacked by an opponent’s piece at the conclusion of castling.”
You should note there is a scenario in the blitz rules where castling queenside would be perfectly legal in this scenario (3a).
This is wrong, because the king would have to pass across that square as well, and a king cannot castle out of check, through check or into check.
And that is explained in the Rulebook too, but again out of caution regarding potentially providing too much information, I’m not sure including that part is relevant in terms of answering the question regarding the rook.
I’ve heard the Korchnoi story more than once. Apparently it occurred at a FIDE event (possibly part of the WC cycle) and the arbiter was astonished that Korchnoi didn’t know that rule.
His response: It had never come up before.
This section of Edward Winter’s article on Castling in Chess describes the Korchnoi incident, as well as other similar uncertainties about the rules of castling.
The rest of 8C1c is “but this is impossible as the king would have to illegally cross the attacked square to bring it about.”
PS the Blitz 3a comment would apply to kingside castling (with the h-file rook) when the king was set up on the d file and the queen on the e file. In that case the h-file rook could pass over an attacked g file square and castling would still be allowed (king moving from d file to f file).