Single Comment

>> My intention was that castling, championing and centauring would
be as near as possible in meaning to castling in ordinary chess...

> The hardest thing about coding the rules for castling etc. in
Zillions is the stipulation not found in ordinary chess, 'that
the king has not been checked at any previous time in that game.'

Well, it was only after reading the recent Rules of Chess: Castling FAQ
document that I realized that 'provided that the king has not been
checked at any previous time in that game' is not how ordinary chess
works.

http://www.chessvariants.com/d.chess/castlefaq.html

I thought about changing the rules of Tree garden chess to suit this but
did not do so as you were already preparing a Zillions of Games
implementation.  However, I am pleased now to change the rules of Tree
garden chess so that castling, championing and centauring is not stopped
if the king has previously been checked as long as the king has not been
moved, thereby making the rules of Tree garden chess as much like those
of ordinary chess as possible.

I am also similarly changing the rules for Herb garden chess so as to be
the same as for Tree garden chess in relation to castling, championing
and centauring, except as to that the two games have a different number
of champions and centaurs.

So, delete the following from the rules.

Each side may only use castling, championing or centauring once in any
one game and provided that the king has not been checked at any previous
time in that game and provided that both the king and the participating
piece have not moved previously during the game.  Castling, championing
and centauring may only take place if the king is not in check at the
start of the process, does not pass across a square which is under attack
and does not end upon a square which is under attack.

Add the following to the rules in the place from where the above was
deleted.

Each side may only use castling, championing or centauring once in any
one game and provided that both the king and the participating piece
have not moved previously during the game.  Castling, championing and
centauring may only take place if the king is not in check at the start
of the process, does not pass across a square which is under attack and
does not end upon a square which is under attack.  If a king has been
previously checked in a game, the fact of that king having been
previously checked in the game does not prevent castling, championing
or centauring taking place.

Thank you for pointing this out.