When en passant is the only legal move

Consider the following position:

``````8/7p/5K1k/8/7p/7P/5PP1/8 w - - 0 1

1. g4 hxg3
``````

In the above postion, White plays g2-g4. The only legal move is hxg3, en passant. I heard someone say that since the en passant capture is optional, Black can refuse to play it and have the game declared a draw by stalemate. I think this is nonsense and believe that as long as there are legal moves available there's no stalemate.

Who is right?

• Capturing en passant is the weirdest move in chess. When someone was taught the rule, they were told it was optional - because it is. Now they have confused "optional to play an en passant capture" with "moving is optional because en-passant is optional". It is easy to see how someone could make that mistake. Dec 30, 2015 at 17:42
• Its optional in the same way that every other move in chess is optional. At the end of the day you still need to pick one of them though. Dec 30, 2015 at 18:29
• It is only optional if you have another option :-) Dec 30, 2015 at 19:02
• Capturing en passant is a legal move. There is no such thing as an „optional“ move in chess. Nov 10, 2020 at 12:18

You are right, this is nonsense. From the FIDE laws of chess, article 5:

The game is drawn when the player to move has no legal move and his king is not in check. The game is said to end in ‘stalemate’.

If capturing en passant is possible, it is a legal move so if it is the only option, Black is required to play the move. (Or not to move at all and lose through the clock.)

• Indeed. En-passant is no more and no less an "optional move" than any other move. The idea that it was an option that a player may choose not to take was the basis of a joke in Fraenkel's Adventure in Chess (1951, published under the pseudonym Assiac). Unfortuntately I no longer have a copy to check, but the position Fraenkel used might even be the one in @Andrea's OP. Jun 4, 2016 at 5:59
• I believe you mean this position? I’m just here to help! futilitycloset.com/2010/06/09/intercepted Apr 29, 2019 at 21:28
• @RewanDemontay Unfortunatelly, whoever made the website you link made a mistake setting up the first position! Aug 29, 2019 at 7:11
• @RewanDemontay Nice philosophical question posed in the link. of course the rules address who's right, but this question seems to be directed at what the rules should be rather than what the rules are. (normative instead of positive)
– BCLC
Aug 4, 2020 at 4:23
• @RewanDemontay Correct book, and close, but that wasn't quite the example I was thinking of. IIRC it was another example in the same chapter. Feb 14 at 18:48