From: Benjamin Auder Date: Fri, 25 Nov 2022 16:57:25 +0000 (+0100) Subject: Work on Checkered variant X-Git-Url: https://git.auder.net/doc/html/assets/current/git-favicon.png?a=commitdiff_plain;h=1080bc93379cd270e09f7d125e2cb95bda51f95f;p=xogo.git Work on Checkered variant --- diff --git a/variants/Checkered/complete_rules.html b/variants/Checkered/complete_rules.html new file mode 100644 index 0000000..5f21663 --- /dev/null +++ b/variants/Checkered/complete_rules.html @@ -0,0 +1,152 @@ + + + + Checkered Rules + + + + + +
+

Checkered Rules

+ +
+

+ The capture of an enemy piece produces a new "checkered" piece belonging + to both players. +

+
+ + + + + +
Checkered pieces, born after captures.
+
+

Note: the initial French name for this variant is "l'Échiqueté".

+

The game potentially evolves in two stages.

+
+ +
+

Stage 1

+

Basics

+
    +
  1. + Each capture produces a new piece, taking on nature of + the capturing or captured one. +
    2. +
  2. + The new piece arising from a capture has a new color: + "checkered", as illustrated above. +
    3. +
  3. + All checkered pieces belong to the player in turn and can + capture the opponents pieces. +
    4. +
+

Remarks:

+
    +
  • + A non-capturing checkered move cannot be "undone" right after since + this would repeat the same position. +
    • +
  • Checkered pieces cannot be captured.
    • +
+
+
fen:2kr4/pp6/2p5/4ss1r/1P2ns1P/2Np4/P1P1P1BP/R2o1RK1:
+
+ Black plays Rxh4=P. (Checkered pawn to) h5 is allowed then, + because piece's nature changed. + +
+
+

Pawns

+
    +
  • + Pawns can jump two squares only from their initial rank, and only once in + the game. A checkered pawn keeps this right if the starting pawn + did not use it. +
    • +
  • + Checkered pawns cannot capture en passant, because while the pawn was + "passing" they were of the same color. + +
    • +
+

Stalemate or checkmate?

+

+ The following diagram seems to show a mating pattern, but the king if + "attacked" by a checkered pawn – which still belongs to white. + Therefore, it can be considered that it's not really a check because + white is unable to "give back the turn". + Without the black bishop on a7 it would be mate (without debate), because + the king could virtually go to g1 before being captured by the + chameleon pawn. + +

+
+
+
+
After 1...g2+(#?).
+
+

+ The interface considers that it's mate in both cases, following the idea + "it's checkmate if we cannot move, and the opponent on its turn could + take the king" (maybe after an impossible move). + +

+
+ +
+

Stage 2

+

+ This stage can be disabled by unselecting "With switch" at game creation. +

+

+ During the game one of the two players can decide to take control of the + checkered pieces. + They thus become autonomous and vulnerable to being captured - stage 2 + begins. The other player is in charge of both the white and black pieces, and + tries to eliminate checkered pieces. + The checkered side wins by checkmating either the white or black king. +

+

+ To take the checkered pieces, play a move that "takes opponent's king" with + your king, and then execute a move. This is possible only if no such move + can capture a king. +

+

Variant of stage 2 (unimplemented)

+

+ An observer could decide to join the game by taking the checkered pieces + at any moment. + It then becomes a chess game with three players, with some subtelties to be + resolved. It was tested in some (real life) games. +

+

Special moves

+

Checkered pawns can...

+
    +
  • move and capture in either direction;
    • +
  • take en passant,
    • +
  • be promoted on either the first or eighth row.
    • +
+
+ +
+

Credits

+
    +
  • + The rules of Checkered Chess were thought up by Patrick Bernier and + developed with the help of Benjamin Auder around 2011-2012. +
    • +
  • + Thanks also to Olive Martin, Christian Poisson, Bevis Martin, Laurent + Nouhaud and Frédéric Fradet. +
    • +
+
+ + + + + diff --git a/variants/Checkered/pieces/cb.svg b/variants/Checkered/pieces/cb.svg new file mode 100644 index 0000000..3f32179 --- /dev/null +++ b/variants/Checkered/pieces/cb.svg @@ -0,0 +1,173 @@ + + + + + + image/svg+xml + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + diff --git a/variants/Checkered/pieces/cn.svg b/variants/Checkered/pieces/cn.svg new file mode 100644 index 0000000..5f7b3bc --- /dev/null +++ b/variants/Checkered/pieces/cn.svg @@ -0,0 +1,101 @@ + + + + + + image/svg+xml + + + + + + + + + + + + + + + + + diff --git a/variants/Checkered/pieces/cp.svg b/variants/Checkered/pieces/cp.svg new file mode 100644 index 0000000..39a8b13 --- /dev/null +++ b/variants/Checkered/pieces/cp.svg @@ -0,0 +1,86 @@ + + + + + + image/svg+xml + + + + + + + + + + + + + + diff --git a/variants/Checkered/pieces/cq.svg b/variants/Checkered/pieces/cq.svg new file mode 100644 index 0000000..bf3e849 --- /dev/null +++ b/variants/Checkered/pieces/cq.svg @@ -0,0 +1,189 @@ + + + + + + image/svg+xml + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + diff --git a/variants/Checkered/pieces/cr.svg b/variants/Checkered/pieces/cr.svg new file mode 100644 index 0000000..1923486 --- /dev/null +++ b/variants/Checkered/pieces/cr.svg @@ -0,0 +1,143 @@ + + + + + + image/svg+xml + + + + + + + + + + + + + + + + + + + + + + + + + + diff --git a/variants/Checkered/rules.html b/variants/Checkered/rules.html new file mode 100644 index 0000000..892f352 --- /dev/null +++ b/variants/Checkered/rules.html @@ -0,0 +1,10 @@ +

+ Each capture produces a new "checkered" piece which both players can use. + Checkered moves cannot be undone on next turn. +

+ + + Full rules description. + + +

Patrick Bernier (2012).

diff --git a/variants/Checkered/style.css b/variants/Checkered/style.css new file mode 100644 index 0000000..a6582e7 --- /dev/null +++ b/variants/Checkered/style.css @@ -0,0 +1,17 @@ +@import url("/base_pieces.css"); + +piece.checkered-pawn { + background-image: url('/variants/Checkered/pieces/cp.svg'); +} +piece.checkered-rook { + background-image: url('/variants/Checkered/pieces/cr.svg'); +} +piece.checkered-knight { + background-image: url('/variants/Checkered/pieces/cn.svg'); +} +piece.checkered-bishop { + background-image: url('/variants/Checkered/pieces/cb.svg'); +} +piece.checkered-queen { + background-image: url('/variants/Checkered/pieces/cq.svg'); +}