What "double moves" are sometimes considered legal?

As we know, castling is a legal "double move," where two pieces are moved at once.

But in my country, Indonesia, in my childhood, the opening below was an 'assumed legal' double move to counter `1.e4` and similar openings.

``````[FEN "rnbqkbnr/p1pppp1p/1p1111p1/8/4P3/8/PPPP1PPP/RNBQKBNR - - - 0 0 "]
``````

As I understand, this opening is an illegal double move. (Someone can help me with the FIDE rule.)

I would like to know, though, are such double moves played in any other place in the world??

• Just stumbled upon this question and also as Indonesian, I have also heard this move in my childhood, where white & black's "1st move" can move 2 pieces simultaneously. That confused me a lot, but I didn't ask why. (There was no internet access, so it's hard to gather this kind of info)... probably a local variation of chess game. Jan 6, 2016 at 5:52

From your description, I'm not sure whether in your childhood games the sort of double move you showed above could only happen at that one point in the game, or could continue to happen. So I don't have much to say, but there is at least an established chess variant (dating back to the early 20th century) in which your indicated sequence of moves could occur legally.

The game is (Balanced) Marseillais Chess, in which White begins with a single move, but then each side alternates making two successive moves from that point on. In (essentially) the notation used at that link, your position would arise after

1.e4

1.b6; g6

Other than the fact that each side makes two moves, the rules are essentially the normal rules of chess. There are of course some necessary changes, e.g. if your first move is a check you don't get a second one. Follow the link for full details and some history.

• it just happen for first move. as I liked to move with Ruy Lopez at first move, my friend always flank with `b6` and `g6` together in reply. Then he said that it's legal.. But your link simply encourage me that it really legal for both side if I proposed as White `1. e4 ; d4`.. (I can say that my friend cheated me at my childhood) Oct 4, 2013 at 7:26
• The position can also arise in ordinary chess: 1.e3 b6 2.e4 g6. Dec 12, 2014 at 8:54
• @DavidRicherby, quite right, the position in question can certainly arise legally in standard chess. I should reword my post to speak only to the legality of the move sequence. Thanks.
– ETD
Dec 12, 2014 at 13:07

Castling is the only legal chess move in which two pieces are moved. You can verify this by searching for "FIDE Laws of Chess" and reading "Article 3: The moves of the pieces" (I do not provide the URL here because unfortunately it frequently changes).

• thanks. I'd like to think that FIDE does not provide completely definition about double moves.. I should see Ed Dean's answer first. Oct 4, 2013 at 7:19