vchess.club : play chess variants

Ok, thank you ! I'll investigate (and the Alice case too, almost all is normal but a move made a piece suddenly disappear after 16 normal moves of play :/ )

Alice chess seems finally OK (a bit subtle to code). Not 100% sure about my en-passant rule. I assumed that since pawns "go through the mirror", any pawn can take any other (enemy) one en passant because they can capture them on the way.

I re-checked all variants trying to play a few games, I didn't notice bugs. So I cannot fix the bug you talked about for now, sorry :/ I added a "how-to-report-a-bug" on the welcome page, which should help for future issues. Finally, coming soon: two variants with bigger boards :)

The en passant rule says something like 'pawn standing next to pawn that has done double move, has the right to ...'
I think standing on an other board is not standing next to it. It also says something like 'taking as if the other pawn had only done a singular step'. That can only be done if both are now on the mirror board.

It's a bit unclear. I'll try a game on schemingmind to see how they implemented it. What you say implies that en-passant capture is possible only if both pawns are on the same side at the time of the capture. Makes sense :) Very easy to fix anyway.

schemingmind simplified a lot: "en-passant is not allowed" (www.schemingmind.com/variants.aspx Alice Chess 1). But chessvariants state that these captures are not forbidden by the original rules definition. To me both interpretations are sound.

You: "en-passant is allowed only on Alice board"
Me: "considering that pieces go through a mirror, pawns could capture others on their way to the mirror, or from the mirror to their destination. Which allow any type of en-passant".

I have a preference for the latter because restriciting en-passant captures would force to play 1.e3 2.e4 3.e5 (maybe with captures) to allow it, while the most common 1.e4 2.e5 would not. But some playing experience would help a lot :)

I finished implementing all the targeted variants.

A few known bugs:
- castling in switching chess may show a weird choice (harmless but annoying)
- capturing promoted pieces in crazyhouse give pieces, not pawns.
I'll fix that in a few days. I take a pause now =)

Next I should put some efforts into style, to attract more players.

A bug in crazyhouse: from where comes the rock for 3. ... R@a4 ?

[Site "vchess.club"]
[Variant "Crazyhouse"]
[Date "2018-11-28"]
[White "Myself"]
[Black "Computer"]
[Fen "bbrqnkrn/pppppppp/8/8/8/8/PPPPPPPP/RBBNNQKR"]
[Result "1-0"]

1.d4 c6 2.e4 0-0 3.Nf3 R@a4 4.c3 Rc7 5.Bc2 Ra5 6.b4 Rh5 7.Ne3 f6 8.Qc4 e6 9.Bd1 Rf7 10.Nd2 Rg5 11.Nf3 Rh5 12.Nd2 Rh4 13.Nf3 Rxe4 14.Bc2 @d3 15.Bxd3 Rf4 16.@g3 Rxf3 17.gxf3 N@h3 18.Kg2 Nf4 19.gxf4 d6 20.Ng4 g5 21.fxg5 fxg5 22.@g3 @h3 23.Kxh3 Rxf3 24.Kg2 Rxd3 25.Qxd3 @h3 26.Kxh3 B@g2 27.Kxg2 Ng7 28.@f6 a6 29.fxg7 Kxg7 30.@f6 Kf7 31.R@g7 Kf8 32.R@g8 1-0

Oh and after trying I have two other questions:

1. In switching you do not seem to be able to switch a pawn for another pawn. (That could be important in pawnendgames.) Why?
2. At a promotion in wildbeast I only got the options queen and wildbeast. Why? (Also please note that I didn't promote anything while trying grant - if something like this happens there aswell my question also applies there)
Also thanks again for your work with the site.

Thanks for the bug report (and more generally for testing my website :) ). No idea for now :/ I'll take a look.

About the last message:
1. A switch with a similar piece is equivalent to no move at all, thus forbidden. I'm not sure if I said that in the rules. I should.
2. Because the rules say so ^^ Grand promotion rules are a bit complicated, have a look e.g. at the chessvariants.com pages.

I understood where the mysterious rook come from: castle is erronously considered as a capture (of a rook...). I fix that now. I fix also the evaluation function which didn't take reserve pieces into account ^^ Online in a few minutes.