Rules of chess: any situations where you MUST resign?

No, but there are times when I wish I could reach through the screen and hit the resign button for them. In most cases, I would really be doing them a favor.

There's no rule in chess that says one must resign.

The main point of that scene wasn't to demonstrate proper chess, but to create dramatic conflict (he wanted her to resign; she refused).

It also established Beth as a determined player who hates to lose.

Sounds like a bad film. I watched a netflix film called "The War Below", set in the First World War", with my wife the other night. We both thought that it was also a bad film ... badly directed and scripted but we watched it because it was filmed in the Beamish museum. The accents were completely wrong (no public (ie private) school accents for the officers so that the generals were lower middle class), they had people thanking each other "for their time" and the plot had some tunnelers being sent to no-man's land, where they might have been captured by the enemy and killing themselves because they didn't get a letter from their girlfriend. And there was a high ranking staff officer determined to undermine Haig's efforts, which would have got him demoted or made Governor of the Falklands. Complete rubbish, written by people with no idea of much at all.

     Concord, CA where the tournament in question was held, is in the San Francisco Bay Area. You know, the place where the PC or smartphone you are using came from.

That's stalling. You can report such players: https://support.chess.com/article/675-what-is-stalling

I just played on in a dead lost position, for the past three or four days, as I explained elsewhere, because I thought my opponent was a bit iffy, for a reason I won't state. Today he was banned for unfair play.

PLEASE SPARE ME KIND SIR, FOR I HAVE LOST MULTIPLE PIECES IN THE GAME OF CHEESE

I believe I'm not dead: therefore I haven't been born yet.

To add to my old text, I found this https://www.chesshistory.com/winter/extra/stalemate.html somewhere in the early sections of the article (after the first picture with the starting words "the king is on no account..."

I suspect that this is the only instant where resignation might have to be forced if the game does not run on any time control.

I try not to resign but there are certain situations that I know I should, for example; when I start the game.

Sometimes down material can still be playable.  Once I went down a queen, but then I left my opponent with just 5 pawns vs my rook and pawn, and my opponent resigned.

I am confused, @eric0022. How does the fact that stalemate was formerly considered a win (not a draw as per the current rules) have anything to do with whether or not resignation is ever required? (Btw, resignation is NEVER required--even in your scenario. In a casual game with no clock, the game would simply continue irrespective of any actions by either player other than resignation.)

thats really cool!

If en passant is the only legal move for Black in the game to evade checkmate (diagram in post #84), but Black is not aware of the en passant move, then things will get complicated. On one hand, Black thinks he is checkmated. On the other hand, White will say that the game has not ended yet.

If Black does not play the en passant move, who would win the game? There is no timeout in a timeless game.

Black's inability to realise the move shows that he is incapable of continuing the position (and thus, Black would be considered to be lost). But legally, he is not lost yet. That game can only end by resignation...or by adjournment (well, you can't expect White to point out to Black about the en passant move...Black ought to find it out himself somehow).

The position in post #84 was roughly about the position I once faced in an actual game many years ago on a different website (except I couldn't remember the position of the rooks - but I know that the White rook was along that rank). It was one of the two occurrences leading to me learning the en passant.

At the time I had not known en passant yet. I held the White pieces and I could not remember if it was a timed game or not - though I believe it was.

I played b2-b4, expecting checkmate. No checkmate message popped up. I waited for some time, but nothing - no checkmate.

What I did not realise back then was, my opponent also did not know about the en passant move! The game went more than ten minutes, with me wondering what could possibly go wrong (remember, neither of us knew the en passant at all).

Suddenly (I think it was about 15 minutes into the position), my opponent finally played en passant (likely through reading of the rules of chess again). I was like "OMG, A GLITCH, THE COMPUTER HAS GONE BONKERS!".

Now, imagine my opponent had not seen that move. And imagine the game was timeless. How would the game end then if neither of us knew how to make the en passant move? Both of us believed it was checkmate, but the system did not end the game immediately.

Though resignation is not forced in that situation in the absolute terms, Black should accept that he has lost the game (if he has not learned the en passant game, that position would be equivalent to him getting checkmated). This is why White should win - but because the system does not recognise this, the game will not end. Thus, the game can only end upon a resignation, a successful draw offer, a disconnection or some adjournment.

whether or not a player is aware of the rules of chess is irrelevant. he is not 'forced' to resign under any circumstances. if the game is rated there will be some sort of time component involved and he will eventually time out for the loss. if it just a casual game with no rating and no clock involved, he is allowed to take an infinite amount of time to make his move. from a practical standpoint, most reasonable people will resign under such a scenario, but the answer to the question remains 'no.' resignation is never mandatory in chess.

agreed