The Etiquette of "Check"

As a beginner, I was told (like most beginners) that it is mandatory to say "check" when you make a move that puts the other player in check.   Later, I learned somewhere that it would be bad etiquette to tell a master that he is in check.  Early this year, I went to a fundraiser for a semi-local school chess club that was sending some of its best to Nationals and SuperNationals (the only time I've ever had the chance to play OTB against someone else who takes the game seriously; we had to adjourn indefinitely on move 17).  While there, I heard that it's not mandatory to say announce check, but that it's considered good etiquette.  Then, a few months later, I got to visit with one of the top players from that school club, who told me that when he went to Nationals, he found that in that setting it was considered rude to say "check."

I'm confused.  When is it considered mandatory, good manners, or bad manners to announce check?

I don't shake hands, I tip my king. gotta stick with the classics.

any club / tournament setting it is consider rude to say check for 2 reasons, it breaks the silent atmosphere, and implies you don't think your opponent can see that he is in check. doesn't mater if they're rated 600 or 2800

Only time you should really talk during a tournament game is if you're offering a draw.

Sometimes in tournaments I say check. It causes everyone in the room to look. At larger, more serious tournaments, I restrain myself. In casual play I say check when I feel like being obnoxious.

ive played against a 6 yr old asian kid recently and he did not say check, one b/c of atomshpere, and two b/c he took my king b/c i did not notice a pin, and i lost the game

so if your opponent does not see it then its game over,

p.s watch the game closely

In tournament play, just don't say anything except when offering a draw. (Well, if the tournament isn't extremely serious, I also offer my opponent a drink when I'm getting one)

I think FIDE rules now are  that you don't have to say 'check' and if your opponent does not notice it, then you capture the K - game over. For sure this applies to blitz games

Well, in blitz, illegal moves lose the game. But under FIDE rules, capturing the king is itself an illegal move! The correct thing to do is to stop the clock and call the arbiter (or usually, just say "illegal move" and the opponent will acknowledge it). But don't capture the king!

In slow chess, if it is found that an illegal move has happened at any point previously (may be hours ago), then the old situation has to be reinstated, the arbiter has to make a good guess as to what the clocks probably were when the move happened, the opponent gets 2 minutes extra time, and the game continues.

Of course it's usually noticed immediately, and it just gives your opponent the 2 minutes extra time. If the arbiter is competent enough to know this...

I thought you couldn't capture the king in chess. Thay's why it would seem the right procedure to say check.

The king never leaves the board.

I only say check if my opponet tries to make another move that doesn't get them out of check.

Woah, that would be an easy win!

I mean, these people have played chess before. They should know that their king is being checked!

Checks are quite obvious. Checkmates aren't so much, though. A great example would be Tarrasch.

In tournament chess check is not normally announced. There is no rule ( that I am aware of ) making it mandatory nor is there one forbidding doing so. However, its usually not announced because if your opponent doesnt notice that they are in check and tries to make an illegal move then it could easily cost them the game and every tournament player is trying to win... There is also the problem that announcing check may disturb neighboring players, especially with those players who like to shout it out or otherwise make some "show" out of their announcement.

tricky discoved moves r worth anoncing chek but qeen excanges sutch as philadors defence where d1 x d8 1the queen is going next move and stting next to the king on e8 makes it a give away so it is not worth anonucing

 Why would you announce check in a tournament game when its to your advantage if your opponent doesnt notice he's in check ?

This is really interesting.  I went to a chess club last night for the first time ever, and I had no idea about this etiquette regarding check. 

I used to think that announcing a ´check´was obligatory in normal OTB chess with slow time controls, at the other hand not obligatory in Rapid chess, where the king indeed can be captured and the game won. But maybe I am just confused on the first point?

 In tournament play announcing check is never obligatory. Also, actually capturing the king is never allowed in tournament play ( FIDE rules ) even in rapid or blitz time controls. I am not sure if uscf rules differ or not here.

announcing "check" needs to be forbidden in tournament play. It's unnecessary and disrupts people's other games.

If you want to indicate to your opponent that they are in check , without saying anything, simply point to their king. I have done this a few times over the years and they always get the message and I have not disturbed anyone.