Check out Glinski's Hexagonal Chess, our featured variant for May, 2024.

Enter Your Reply

The Comment You're Replying To
H. G. Muller wrote on Mon, Mar 25, 2013 01:44 PM UTC:
Indeed, this is what I meant. That the Fairy-Max derivative that plays Alice Chess does it this way is completely accidental; initially I had misunderstood the rules to be such that moves had to be pseudo-legal on the board they were played, and that you only had to worry about your King being capturable after the transfer. This made it virtually impossible to checkmate a King, though, as he keeps fleeing to the other board.

So I patched it for not being allowed to pass through check. Internally it uses the single-board representation, and a flag in the piece code to indicate on which board it is. That flag is toggled every time you move the piece. When a move attempts to go to a square that is occupied by a piece marked as being on the other board, that square counts as empty and the non-capture move rights for that square are suppressed. Those were basically the only changes that were needed to make it play Alice Chess, except for this passing-through-check rule. So I later patched the code to make the test for royalty of the victim before it checks on which board it is, and if it is on the other board, abort due to King capture only if that square is also the to-square of the previous move (which was passed from parent to daughter node anyway for implementing Berolina e.p. captures).

This catches passing through check on any King move, but there is no test for King capture between making the move N transfering to the other board. A move going over that square would either skip over the square on the board you just left, but would block any moves over that square on the board you just arrived on. To implement the other rule interpretation, it would have to continue moves through the to-square of the previous move, solely for the purpose if there was a King behind it. It does not do that.

Note that the "legal if strictly legal on the board it is played" interpretation is flawed anyway, because it would allow you to legally put your own King in check: white Ke1, Pe2, black Qe8 (all on same board) would have e2-e4 legal, because before you transfer e4 to e4*, your King is not yet in check.

Edit Form

Comment on the page Alice Chess

Conduct Guidelines
This is a Chess variants website, not a general forum.
Please limit your comments to Chess variants or the operation of this site.
Keep this website a safe space for Chess variant hobbyists of all stripes.
Because we want people to feel comfortable here no matter what their political or religious beliefs might be, we ask you to avoid discussing politics, religion, or other controversial subjects here. No matter how passionately you feel about any of these subjects, just take it someplace else.
Quick Markdown Guide

By default, new comments may be entered as Markdown, simple markup syntax designed to be readable and not look like markup. Comments stored as Markdown will be converted to HTML by Parsedown before displaying them. This follows the Github Flavored Markdown Spec with support for Markdown Extra. For a good overview of Markdown in general, check out the Markdown Guide. Here is a quick comparison of some commonly used Markdown with the rendered result:

Top level header: <H1>

Block quote

Second paragraph in block quote

First Paragraph of response. Italics, bold, and bold italics.

Second Paragraph after blank line. Here is some HTML code mixed in with the Markdown, and here is the same <U>HTML code</U> enclosed by backticks.

Secondary Header: <H2>

  • Unordered list item
  • Second unordered list item
  • New unordered list
    • Nested list item

Third Level header <H3>

  1. An ordered list item.
  2. A second ordered list item with the same number.
  3. A third ordered list item.
Here is some preformatted text.
  This line begins with some indentation.
    This begins with even more indentation.
And this line has no indentation.

Alt text for a graphic image

A definition list
A list of terms, each with one or more definitions following it.
An HTML construct using the tags <DL>, <DT> and <DD>.
A term
Its definition after a colon.
A second definition.
A third definition.
Another term following a blank line
The definition of that term.