| 1 | p.boxed |
| 2 | | Move twice at every turn. |
| 3 | |
| 4 | p. |
| 5 | The only difference with orthodox chess is the double-move rule, |
| 6 | but this affects the game a lot. |
| 7 | |
| 8 | p. |
| 9 | At the very first move of the game, white make only one move - as usual. |
| 10 | However, after that and for all the game each side must play twice at |
| 11 | every turn. There are two exceptions: |
| 12 | |
| 13 | ul |
| 14 | li. |
| 15 | If the first move gives check (maybe checkmate), |
| 16 | then a second move isn't played. |
| 17 | li. |
| 18 | If no move is available after the first move, then it's stalemate |
| 19 | and again, there is no second move. |
| 20 | |
| 21 | p. |
| 22 | About the PGN game notation: when a side plays two moves in a row, |
| 23 | they are separated (in order) by a comma in the PGN. |
| 24 | Example: 3.Na5,Bd3 e6,f4 (the two first are white moves, |
| 25 | the two others are black moves). |
| 26 | |
| 27 | figure.diagram-container |
| 28 | .diagram |
| 29 | | fen:r1bqkbnr/pppp1p1p/2n5/4p2p/4P3/5N2/PPPP1PPP/RNB1KB1R: |
| 30 | figcaption After the moves 1.e4 e5,Nc6 2.Qh5,Nf3 g6,gxh5 |
| 31 | |
| 32 | h3 En-passant capture |
| 33 | |
| 34 | p. |
| 35 | Capturing en-passant is allowed under certain conditions. |
| 36 | If the opponent moved a pawn allowing such a capture (once or twice), |
| 37 | then (to take it) you must capture en-passant at the first move of your turn. |
| 38 | After that, if (and only if) there is another en-passant capture available |
| 39 | you can play it on the second move. |
| 40 | |
| 41 | p. |
| 42 | Note: if a pawn 2-squares jump was made and then a piece landed at the |
| 43 | en-passant square at the second move, a pawn capture on this square |
| 44 | takes only the piece. |
| 45 | And, if a pawn advanced twice then en-passant capture |
| 46 | on its first movement is impossible (the pawn is now "too far"). |
| 47 | |
| 48 | h3 More information |
| 49 | |
| 50 | p |
| 51 | | See for example the |
| 52 | a(href="https://www.chessvariants.com/multimove.dir/marseill.html") |
| 53 | | Marseillais Chess |
| 54 | | page on chessvariants.com. |
| 55 | |
| 56 | p |
| 57 | | Inventor: Albert Fortis (1922) - disputed according to |
| 58 | a(href="https://fr.wikipedia.org/wiki/%C3%89checs_marseillais#Histoire") |
| 59 | | this historical note |