Well, to be fair, it’s kind of hard to telegraph (though not impossible) that simply in a comic or live action, so the narrative shortcut of players saying “check” or “checkmate” work fine for me as a narrative shortcut/device, as the audience would be familiar with that from informal games.
Reminds me of the fake tell by Bond’s opponent in the Daniel Craig Casino Royale.
Sound like the meme, If you don’t spot the fish when you sit down at the poker table, it’s you.
To be clear…this is said by two people. More often then not the villain says check and the hero checkmate.
Villain: “Check”
Hero: “Checkmate”
But ‘to be faiirrrrrr’…In an informal setting, you’d say it out loud. And it robs all the dramatic tension if the more realistic following happened:
Villain: “Check…oh shit…I resign”
I actually had a very similar situation in my first “real” over-the-board game against an (I believe) 8-year-old recently.
I have been playing a bit online since I started running my son’s elementary-school chess club trying to brush up to be able to get these absolute beginners familiar with the game. I decided if I’m going to encourage them to play some scholastic tournaments I should at least do it myself, so I got a USCF membership and played some local rated games.
In my first match against this kid I thought I had a sound tactic to sacrifice a piece to trap his knight only to realize that if I actually recaptured the knight (on one particularly square) I was open to a back-rank checkmate. My opponent picked up his knight, dramatically moved it to all of the possible squares, and then sighed and put it on the one where if I captured it I would get checkmated.
I eventually lost the match (this kid is good!) but afterwards I asked him “why the dramatics?”. So now I ask @glee and others - is it OK to dramatically “lose” a piece to set a trap? I am not a good player, but even I saw through the subterfuge, so it seemed poor sportsmanship to me, but perhaps there is no such thing in competitive chess?
OK, I confess, I have never seen this. I’ve seen “check … and mate!” by the hero or protagonist or whatever, but not a “check” by one player followed by “checkmate” by the other.
I have a tiny fraction of glee’s chess experience, but I would say it is poor sportsmanship, yes. I’m glad you raised it after the game - the kid, who is obviously a smart kid already, thought he was being smarter still by doing this - probably quite innocently, not realising it was a breach of etiquette. If he’s a good kid, your quiet word after the game is probably enough that he’ll never do it again.
Regarding poker, there is an old video and a bit of discussion in this Reddit thread: https://www.reddit.com/r/poker/comments/1rnnz8/new_to_poker_this_is_an_old_video_clip_showing_a/ - basically a player has a strong hand, thinks about it, says “raise” (verbal bets are binding) but then tries to claim he doesn’t understand English and meant to say “call”. His angle being that he is hoping to convince the other player that his hand is weaker than it really is, and induce them to call his raise (which he knows he will be obliged to make, having announced it), when otherwise they may not have done. The tournament director is called and discloses that he has seen this player pull the same tactic before, with a very strong hand. As I recall (I can’t rewatch the video right now), the other player calls anyway, and loses. Virtually every experienced poker player agrees it was a shitty move by the angle shooter, way beyond what is acceptable even in the bluffing, lying world of tournament poker.
Is that even allowed? I thought that if you are in check, you must use your turn to get out of it, either by moving your king to a safe spot, capturing the piece that puts you in check, or moving a piece to block the check. Is my understanding of the rules flawed, or does speed chess have some special set of rules?
Neither - it’s not allowed. The point was that the grandmaster (due to the time pressure) overlooked the check to their own king, and made an illegal move in not addressing it. Our hero (glee) also didn’t realise the error immediately, making a further move before pointing out the original illegal move. And in most rulesets for speed chess, if you make an illegal move you forfeit the game. Although I think there have been some recent controversies wherein a player has (like in glee’s story) not immediately noticed an illegal move by their opponent, then made an illegal move themselves, and lost on that basis (which seems harsh, but I don’t know the details).
It’s a bad idea in a couple of ways!
Firstly waving pieces around dramatically comes under the heading of ‘distracting your opponent’ (breaking the rule mentioned earlier in the thread.)
Secondly acting means you’re not fully concentrating on the game.
Finally setting traps may well work against inexperienced players, but it’s no way to play tournament chess. 
Dead_Cat is spot on! 
I would humbly suggest 2 exceptions to this general rule (there may be others): it’s OK to set a ‘trap’ provided that even if your opponent sees through it, it does your position no harm. Though this is probably a fairly rare situation. More commonly, it may be a reasonable line of play to set a trap if you are in a losing position anyway (or a drawn position but your team needs a win). If the trap works you might manage to salvage a point (or half-point) that you’d otherwise have lost; if it doesn’t, well you had little to lose. This is often known as a ‘swindle’ or ‘playing for tricks’. It can be quite satisfying to pull off (and very irritating for the person who falls for it)!
Dead_Cat, I think it highly unlikely that the best move in a position is to set a trap, even if it does no harm.
However you are quite right about setting a trap in a lost position - after all there isn’t anything better.
However an experienced player will expect ‘trappy’ play if they are winning.
I remember a close-fought game in a league match where our first team was playing our second team. (I was on the second team 
- as our first team was packed full of Grandmasters )
I had gradually been outplayed, so set a cunning trap … my opponent plunged into thought and duly avoided it. Afterwards she said “I knew you were going to try something!”
Fear and ruthlessly efficiency can only get you so far.
When I was a young club player in the 70s, one of my regular opponents had dentures, and he would noisily clack them in and out as he played. I was too inexperienced to complain.
Among all the teenaged players, I had a bete noir- every high school tournament, he inevitably finished first and I finished second. He also had incredible body odor. Was that complainable, I wonder in retrospect? I never did.
He eventually moved to NYC, where his rating cleared 2300. I was visiting the Manhattan and Marshall clubs one day, and saw him in a tournament at the Manhattan. Amazingly, it was still an issue.
Isn’t it technically possible to simultaneously cancel the check and achieve check on your own turn? Say moving the king out the way which leads to a discovered check or even checkmate?
It’s hard to complain when you’re inexperienced.
I remember a Junior County match where my opponent had two possibilities in a difficult position.
The more obvious one lost after a clever continuation (I had seen this!)
Instead of moving, my opponent rudely said “I can move here (indicating the losing move) and it’s a draw.” He offered his hand to agree the draw. 
Of course I should have said either nothing (when his clock is still ticking and he has to move.)
Instead I replied “No, that loses.” 
He promptly played the other move.
That irritated me for a long time.
However I felt (justified?) schadenfreude when years later this same player was cheated in an important tournament.
Your wish is my command!
White: Kb6; Rf3; Bh1
Black: Ka8; Na6
- Rf8+ Nb8+
- Kb6 1-0
Diagram here:
By the way…in the category of “Star Trek predicted it.”, I never see mentioned “Trek predicted that it would become impossible for a human (or Vulcan) to beat a computer at Chess.” Even Three Dimensional Chess.
Hell I’m not even sure if the best a person could hope for is a draw today, as Spock says, never mind in 2266.
Technically possible, but very rare.
I was once in a play where a couple of the actors were supposed to play a game of chess, and the stage directions only had two moves each. The director tried to teach them to do the Fool’s Mate correctly, but I think they ended up just moving random pieces on stage.