This variant was a submission for the large-variant contest. It is the subject of this weeks interactive diagram.
This variant has some funny rules that required special attention.
One was promotion: not only Pawns promote, but a Prince reaching last rank can optionally promote to Queen too.
And a Ship can promote to Griffon in the last-rank corners.
This was handled by defining Prince as first piece,
and specifying only one promoting piece, with as only choices Prince and Queen.
This invokes the normal promotion procedure for Princes,
letting the user select from the legend table.
Pawn and Ship make use of the user-supplied JavaScript function WeirdPromotion.
This automatically promotes these pieces when they reach their respective zones,
as in this cases there is no promotion choice.
Another unusual feature of this variant is that, when checkmated,
Kings can swapped with Princes,wherever these are located.
To make the diagram indicate this possibility,
the King was equipped with a universal-leaper move U.
The modality 'x', which was already introduced on non-final legs of multi-leg moves
to indicate relaying of powers,
is now used for indicating such a piece swap with a friendly piece on final (or only) legs.
Adding a plain xU to the King moves would allow it to be swapped with any friendly piece, however.
To single out the Princes, we declared the board to be zonal by providing a JavaScript function BadZone.
This function tests the the target location for containing a piece of the same color as the mover, and declares the to-square invalid if a non-Prince if found.
Tamerlane II
This variant was a submission for the large-variant contest. It is the subject of this weeks interactive diagram.
This variant has some funny rules that required special attention. One was promotion: not only Pawns promote, but a Prince reaching last rank can optionally promote to Queen too. And a Ship can promote to Griffon in the last-rank corners. This was handled by defining Prince as first piece, and specifying only one promoting piece, with as only choices Prince and Queen. This invokes the normal promotion procedure for Princes, letting the user select from the legend table.
Pawn and Ship make use of the user-supplied JavaScript function WeirdPromotion. This automatically promotes these pieces when they reach their respective zones, as in this cases there is no promotion choice.
Another unusual feature of this variant is that, when checkmated, Kings can swapped with Princes,wherever these are located. To make the diagram indicate this possibility, the King was equipped with a universal-leaper move U. The modality 'x', which was already introduced on non-final legs of multi-leg moves to indicate relaying of powers, is now used for indicating such a piece swap with a friendly piece on final (or only) legs.
Adding a plain xU to the King moves would allow it to be swapped with any friendly piece, however. To single out the Princes, we declared the board to be zonal by providing a JavaScript function BadZone. This function tests the the target location for containing a piece of the same color as the mover, and declares the to-square invalid if a non-Prince if found.