2 | The capture of an enemy piece produces a new "checkered" piece belonging
5 figure.showPieces.center-align
6 img(src="/images/tmp_checkered/cp.png")
7 img(src="/images/tmp_checkered/cr.png")
8 img(src="/images/tmp_checkered/cn.png")
9 img(src="/images/tmp_checkered/cb.png")
10 img(src="/images/tmp_checkered/cq.png")
11 img(src="/images/tmp_checkered/no_ck.png")
12 figcaption Checkered pieces, born after captures.
14 p Note: the initial French name for this variant is "l'Échiqueté".
19 li Chessboard: standard.
20 li Material: additional checkered pieces.
21 li Non-capturing moves: standard; see below.
22 li Special moves: standard; see below.
23 li Captures: standard; see below.
24 li End of game: standard.
26 p The game potentially evolves in two stages.
28 h2.stageDelimiter Stage 1
34 | Each capture produces a new piece, taking on nature of
35 | the capturing or captured one.
37 | The new piece arising from a capture has a new color:
38 | "checkered", as illustrated above.
40 | All checkered pieces belong to the player in turn and can
41 | capture the opponents pieces.
46 A non-capturing checkered move cannot be "undone" right after since
47 this would repeat the same position.
48 li Checkered pieces cannot be captured.
50 figure.diagram-container
52 | fen:2kr4/pp6/2p5/4ss1r/1P2ns1P/2Np4/P1P1P1BP/R2o1RK1:
54 Black plays Rxh4=P. (Checkered pawn to) h5 is allowed then,
55 because piece's nature changed.
61 Pawns can jump two squares only from their initial rank, and only once in the game:
62 a checkered pawn returning on the pawns' start rank cannot jump. However:
64 A pawn captured on its starting square (thus becoming "checkered") keeps the
65 right to advance two squares.
67 Checkered pawns cannot capture en passant, because while the pawn was "passing"
68 they were of the same color.
70 p.bold.bigfont If you wanna play, you can stop reading here.
72 h3 Stalemate or checkmate?
75 The following diagram seems to show a mating pattern, but the king if
76 "attacked" by a checkered pawn – which still belongs to white.
77 Therefore, it can be considered that it's not really a check because
78 white is unable to "give back the turn".
79 Without the black bishop on a7 it would be mate (without debate), because
80 the king could virtually go to g1 before being captured by the pawn-chamaleon.
82 figure.diagram-container
84 | fen:7k/b5pp/8/8/8/8/6ss/7K:
85 figcaption After 1...g2+(#?)
88 The interface considers that it's mate in both cases, following the idea
89 "it's checkmate if we cannot move, and the opponent on its turn could
90 take the king" (maybe after an impossible move).
92 h2.stageDelimiter Stage 2
94 p.warn This stage is not (and probably will never be) implemented.
97 During the game one of the two players can decide to take control of the
99 They thus become autonomous and vulnerable to being captured - stage 2 begins.
100 The other player is in charge of both the white and black pieces, and tries to
101 eliminate checkered pieces.
102 The checkered side wins by checkmating either the white or black king.
104 h4 Variant of stage 2
106 An observer could decide to join the game by taking the checkered pieces
108 It then becomes a chess game with three players, with some subtelties to be resolved.
109 It was tested in some (real life) games organised by the variant creator.
113 p Checkered pawns can...
115 li move and capture in either direction;
117 li be promoted on either the first or eighth row.
123 The rules of Checkered Chess were thought up by Patrick Bernier and developed
124 with the help of Benjamin Auder.
126 Thanks also to Olive Martin, Christian Poisson, Bevis Martin, Laurent Nouhaud