Question concerning illegal chess move(s)

I've got a question concerning illegal chess move(s), I read a book where somebody castled after moving their king but was allowed to continue the game because his opponent didn't notice. So my question can this be legal in any circumstance (like if your opponent doesn't notice an illegal move, like moving into check) Is this considered legal or is it allowed?

Originally posted by daniel58
I've got a question concerning illegal chess move(s), I read a book where somebody castled after moving their king but was allowed to continue the game because his opponent didn't notice. So my question can this be legal in any circumstance (like if your opponent doesn't notice an illegal move, like moving into check) Is this considered legal or is it allowed?

Like you said, if it is not noticed by either player, the game continues unchanged. If it is noticed, in a tournie, you call an arbitrator and they make the call.

There's something of a statute of limitations regarding illegal move claims in most live tournaments. In the USCF, for example, an illegal move must be called within 10 moves or it is allowed to stand.

AS a former tourney PLAYER in the USCF, I can answer. But first, we must clear something up. If no one notices the "illegal" move, then how can one STATE that an illegal move was made? In order to state that an illegal move was made, then ONE must have noticed it. Hmmmmmmmmmmm. Are you saying that AFTER the game, the moves were analyzed and an illegal move was found? If you are, then the GAME STANDS.

However, if during play, the illegal move has been SPOTTED, then the pieces must be returned to the position before the illegal move was made. When I PLAYED in the USCF (80's and 90's) there was NO time limit or statute of Limitations. If you are on move 30 and move 4 was illegal, you RESET to move 3 and the arbiter resets the clocks.

Teacher has it right as far as I can see.

As soon as the game is over the result stands.

It should be added that touch move still stands.

If a player makes an illegal move with a Knight and it is spotted then
he must (if he can) make a move with that Knight.

Often wondered what would happen (and I'm sure it has).
A player makes an illegal move (moves a King pinned piece for instance)
to deliver checkmate.

Very basic example.



White plays 1.Re1 mate.

After agreeing to the lose the loser has lost his right to claim foul
because the game ended.

But the game ended because of an illegal move.
If an illiegal move had not been played then the game would not have ended.

Messy grey area that one.

Originally posted by daniel58
I've got a question concerning illegal chess move(s), I read a book where somebody castled after moving their king but was allowed to continue the game because his opponent didn't notice. So my question can this be legal in any circumstance (like if your opponent doesn't notice an illegal move, like moving into check) Is this considered legal or is it allowed?

3. An illegal move is completed once the opponent’s clock has been started. The opponent is entitled to claim a win before he has made his own move. However, if the opponent cannot checkmate the player’s king by any possible series of legal moves, then the claimant is entitled to claim a draw before he has made his own move. Once the opponent has made his own move, an illegal move cannot be corrected unless mutually agreed without intervention of an arbiter.



The above was taken from the latest version of the Fide rules available at the Fide website.
This was under a blitz chess section.
----
This should not be interpreted to mean illegal moves are allowed.
It is merely a rule for rare situations when an accidental illegal move has occurred.

Originally posted by National Master Dale
3. An illegal move is completed once the opponent’s clock has been started. The opponent is entitled to claim a win before he has made his own move. However, if the opponent cannot checkmate the player’s king by any possible series of legal moves, then the claimant is entitled to claim a draw before he has made his own move. Once the opponent ha ...[text shortened]... allowed.
It is merely a rule for rare situations when an accidental illegal move has occurred.

Aren't the rule differnent in Blitz than in standard though?

Originally posted by greenpawn34
Teacher has it right as far as I can see.

As soon as the game is over the result stands.

It should be added that touch move still stands.

If a player makes an illegal move with a Knight and it is spotted then
he must (if he can) make a move with that Knight.

Often wondered what would happen (and I'm sure it has).
A player makes an illegal ...[text shortened]... iegal move had not been played then the game would not have ended.

Messy grey area that one.

In your example: If White delivers a mate Re8# it isn't a mate only because it seems like a mate. Black can give up the game (as he can whenever he feels like it) and because of that, the game has ended as an agreed and confirmed win for white and lost for black. In that very moment the game has ended, and the result is fixed, and nothing more can be done about it.

The end of this game can be done in a chain of three actions. (1) The verbal aknowledgement ("Mate!" "Yes, it's mate, congrats!"😉, (2) a handshake, and (3) a signature on the protocoll, ever one of these diging the hole deeper fror black. If he mumbles in (1) then he can claim that, "No, I didn't agree to anything, it's not mate because it was an illegal move!" Witnesses would be an help for the arbiter. Then handshake is visual and is not eaily missed by the witnesses. The signature confirmation is the strongest aknowledgement.

But when the game is over, it's over.

(I was once an arbiter in a tournament, when in the analysis after the game, they discovered that the black queen originally stood on e8 instead of d8. (yes it was a lower class tournament.) I asked the participants "Did you agere on the mate?" and both of the players said "Yes", so it was not much to discuss here.)

When shorter thinking times, like 30 min each or something, other rules aplies.