Is there any illegal check mates ?

But the point is this: how can a piece that cannot move be a threat?

Fide laws of chess 3.9:

The king is said to be 'in check' if it is attacked by one or more of the opponent's pieces, even if such pieces are constrained from moving to that square because they would then leave or place their own king in check. No piece can be moved that will either expose the king of the same colour to check or leave that king in check.

That should clear up any doubts. For those who may not understand the reasoning:

The key phrase is "attacked", which is not the same as "able to be taken on the next move". Whether or not a piece is pinned (i.e. it would be illegal to move it) doesn't change its ability to attack a piece or square. That is only a function of the type of piece (bishops capture diagonally, etc.) and not dependant on other board features (like so-called "pins", which aren't explicitly mentioned anywhere in the rules).

yes usually the pinned bishop couldn't move, but in this case it would hypothetically, after Ra7+ capture the king if the king were to capture, and the fact that white's king would be in check wouldn't matter, because black lost his king first!

But why would it matter? The black king is gone so there's no fear in going into check anymore!

The point is that the attacked king cannot escape the attack...nor can he capture the attacking rook (protected by the bishop)...it is irrelevant that the bishop is pinned, since the bishop is protecting the attacking rook from afar, and does not have to move. The main point being that the attacked king cannot capture the rook.

Rule 3.9 does indeed put the matter beyond doubt. Thank you.

However I do not think that the rule needs explaining. It is just the rule, even if it is a rule that produces the oddity that a king is deemed to be attacked even if "attacked" by a piece that cannot move.

супер,гарні були часи)

yea

Oh this is a 13 year old thread..

Anyway, I think the logic behind it is that the reason you can't put your king in check is because it could be taken first, even if your move also puts the king in check. The rules of chess could literally be "capture the king" and there would be no difference. Checkmate by definition is giving the opponent no way from stopping you from taking his king next move, therefore the same logic applies to pinned pieces. If a pinned piece cannot move, it doesn't matter because his king would be taken first. It's the same reason both players can be one move away from checkmate and only the player who checkmate first wins. Actually, one thing this does affect is stalemate, of it were legal to move your king into check, stalemate would be a win in some situations, which is a whole other topic, but essentially, since the king can't be taken, it isn't "defended" from capture the same way a queen is defended from being taken from a knight pinned to the opponents king. Because the game objective is to get the king.

Interesting old thread to see bumped lol. And the nature of the question hits different in a post- duck chess world

Black's king gets captured first, therefore ending the game and resulting in a win for White. ✈

I totally agree with this. I believe a Check by a Pinned Piece must not be considered. Since it cannot move.

So with that same logic, should this be a draw as both players will checkmate each other next move:

The game ends based on what side checkmate first, so even if it was capturing the kings, it would still be based on which one would capture first. The pinned piece would capture the king first, and if the rule was to capture the king first it wouldn't even be pinned, it would be allowed to move, so that's self contradictory.

2. Qd6 is mate.

A win is a win 🙃