In 1970, V. R. Parton, inventor of many chess variants, proposed a
variant where both the king and queen are royal - and isn't that the way
it should be?
Rules
The rules of chess are followed, with the following additions/
modifications:
Just as the king, the queen can be checked and mated. This means that
It is not allowed to make a move such that the queen can be
captured.
When your queen is attacked, you must play a move such that the
queen is no longer attacked.
You lose the game when your queen is attacked and you cannot make a
legal move that avoids the attack.
The rules of check to the king, and mate of the king remain as
always.
Queens may move across attacked squares.
NOST has used the following additional rules
for this variant:
When you promote a pawn to queen, that additional queen also is
royal, i.e., subject to check and mate. Thus, underpromotion, e.g., to
rook may be in many case a better strategy.
Queens can check kings at a distance, but they cannot check queens.
Kings and queens may castle, both long and short, following usual
castling rules.
Comment
Pritchard suggests to forbid queens to pass attacked squares, unless it
captures an attacking piece. Optionally, one could play the game without
letting queens cross attacked squares at all.