Check out Grant Acedrex, our featured variant for April, 2024.

Enter Your Reply

The Comment You're Replying To
H. G. Muller wrote on Mon, Feb 5 04:38 PM UTC in reply to Kevin Pacey from 12:37 AM:

You hit on a major bug in the PTA here. The GAME code generated by the PTA, for efficiency reasons, tries to perform all moves of the game except the last as the game notation specifies them, without any computation. Based on the idea that these moves were already checked for legality earlier, when these were the last move so far. But this does not work for moves with implied side effects, such as castling, e.p. capture and creating e.p. rights. So these moves are considered special, and a computation for them is done even when they are not last, to determine their side effect (like moving a Rook, or removing a Pawn).

The problem was that the Play-Test Applet, when generating GAME code, did not group the ifmW* initial push of the Omega (or Wildebeest) Pawn with these special moves. So their side effect of creating e.p. rights was computed only when they were the last move so far (enabling the highlighting of the e.p. capture in the move to come), but when the e.p. capture was actually played, that became the last move, and the e.p. rights the multi-push should generate were no longer computed, making the e.p. capture illegal.

I now fixed the PTA to also group the W* moves with the special moves. If you want to fix your preset, it might be easier to just modify the code you pasted in the Pre-Game section. Near the end this says:

def P cond #0 1 21;
def p cond #0 32 52;

The 21 here should have been 16, the 52 should have been 47. If you make these changes e.p. capture should work in the preset. I would have done it myself, but it appears that even editors cannot modify other people's presets.


Edit Form

Comment on the page Omega 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.