p.boxed
- | Move twice at every turn.
+ | Move twice at every turn. The goal is to capture the king.
p.
The only difference with orthodox chess is the double-move rule,
p.
At the very first move of the game, white make only one move - as usual.
However, after that and for all the game each side must play twice at
- every turn. The goal is to checkmate.
+ every turn (except if the first move captures the enemy king).
figure.diagram-container
.diagram.diag12
| fen:r1bqkbnr/pppp1ppp/2n5/4p3/2B1P3/5Q2/PPPP1PPP/RNB1K1NR:
figcaption.
Left: after the moves 1.e4 e5, the 'd' pawn is pinned.
- Right: the black king is under check.
+ Right: the black king is "under check".
p.
In the diagram position on the left, after the first black move ...e5,
- the 'd' pawn is pinned because moving it would allow 2.Bb5,Bxe8 capturing
- the king.
- On the right, after 2.Qf3,Bc4 black king is under check because of
- the options 3.Bxf7,Bxe8 or 3.Qxf7,Qxe8.
+ moving the 'd' pawn would allow 2.Bb5,Bxe8 capturing the king.
+ On the right, after 2.Qf3,Bc4 the threats are 3.Bxf7,Bxe8 and 3.Qxf7,Qxe8.
h3 En-passant capture
| . It is also playable
a(href="https://greenchess.net/rules.php?v=double-move") on greenchess
| .
+
+p Inventor: Fred Galvin (1957)