How Can I Create a Variant?

No I'm learning to walk better with 1 knee now. Stay tuned for the next improvement plan.

Gotcha! I'd wish you the best of luck, but instead I'll wish you more of whatever luck you had before!

Are you referring to things like Shogi and Xianqi, for example, when you talk about "chess variants"? Those are not chess variants, they are (like chess itself) variants of an ancient game wich it wasn't named chess. You seem to spot "chess" as the name for this whole family of board games wich share the same concept, and that's incorrect. At the most, you could talk about "Western chess", but FIDE chess? Rules of chess weren't conceived by the FIDE.

About your last statement, you can be sure I know several ways of entertainment far better than chess (one of them is much older than mankind itself), and still I don't find it boring. You probably do, but it's only a matter of taste.

In the middle ages they played Chess, and already called it Chess (or whatever name they still use in the respective countries for referring to the game today). But the rules were different.

You seem to make a point out of Sjatranj and Chaturanga having a name other than Chess, like that would make it a different game, rather than being a consequence of the people playing it at the time speaking a different language. I think that is a folly. Chess isn't even called 'Chess' today, in the largest part of the World. It is called Schach, or Schaken, or Echecs, or Ajedrez. When European people started toplay the Arabic game (Shatranj), they called it by the same name as they are calling the FIDE game today. Early medieval Chess had almost exactly the same rules as Shatranj.

So even if history only starts when people started to use the current name for this family of games, Chess according to FIDE rules is not the game that originally was called Chess, but just a variant of it.

@HGMuller

Sorry man...

The ancient Chess Queen moved one step on the diagonal, just like it does in Thai Makruk.

It never did move like the King.

Ok, but my point is they are not FIDE rules. FIDE has nothing to do with the rules of the game. That's why I said is not FIDE chess.

I never claimed that FIDE invented it. When I say "FIDE Chess", I mean "Chess according to FIDE rules". The latter seems needlessly verbose, and I am a lazy person!

@final_wars

I always assumed that modern Chess evolved from Courier Chess (on 12x8 board) by eliminating the weakest pieces. That would leave the Man on the side of the King where we now have the Queen, while the ancient General (which does move 1 step diagonally), whih had been standing on the opposite side of the King, was eliminated. And that the infinite range of that piece came only later.

In any case, before the 15th century the game was called Chess, and the rules were different. That was my point.

How about hire someone to write a program or do it yourself.

Um... why don't you research IDEs before you post things like this?  It will enlighten you.

Well, if you cannot find what you need, you write something yourself, or take an open-source code that nearly does what you want, and modify it yourself. Then you can always have exactly what you want. It is what I did with WinBoard...

I think c+ might do.

On a serious note, learning to program and dissecting an extant program yourself would be an excellent opportunity, both in general and for this specific application. Even if it does have a greater learning curve, it might work out to be the best route of all.

It is fairly easy to code a program of your own that does that.

Pay somebody to create a variant.

Tell everybody that you created it.

Okay, I've downloaded Sjaak II and have coded the variant.  However, I'm really fuzzy as to how you're supposed to get it to work in Winboard.  What do I do next?

Actually, I've run into an issue, as it appears.  I can't get the variant to load in Sjaak II.

I have the variant coded in, but typing, "variant Morrell" (which is its placeholder name) returns: "Error - Could not start game with variant Morrell."  Before you ask, I have a FEN and the first line is indeed "Variant: Morrell (8x8)" (I also tried, "variant Morrell (8x8)", but that also did not work.)

uhhh...?

this was intersting . let me solve your question that "getting better"means another form of "creative". so in wisdom:Quantitative cause a qualitative change.   that's the perfect answer.

It could be related to the Sjaak II version. Sjaak II originally is a Linux program, and it might expect its variants.txt file in a place where it isn't in the Windows version. (In Linux data files are usually not stored in the same folder as executable programs.) And if it cannot find the file, it would not know about your variant, and only play the variants that are hard-coded in it.

This could be solved by starting Sjaak II with a parameter, e.g. from a command-prompt window typing "SjaakII variants.txt". I thought this problem was solved in the most recent version of Sjaak II, but you might have an older version.

It would be better not to try playing Sjaak II as stand-alone program, however. On Linux you can do this, as it draws a nice ascii board with colored backgrounds. But it uses Linux-specific escape codes for that, which show up as gibberish under Windows. So it is better to run it directly under WinBoard.

I happen to host a package of WinBoard + Sjaak II at http://hgm.nubati.net/SacChess.zip . In that package I have already pre-configured WinBoard to start up with (a very recent version of) Sjaak II as engine. It starts up playing a variant 'Sac Chess', which is defined in the variants.txt file, but you can then switch it to another variant through WinBoard's New Variant menu. So I would strongly recommend using that package. If you put your own variant definition into the variant.txt file of that package (not too much at the end, as that WinBoard has only room for displaying nine engine-defined variants), you should see a radio button for selecting it in the New Variant dialog.

Dude, you're a lifesaver!  I was totally at a dead end here!

I can't thank you enough for that, this is a real breakthrough.  However, I have run into a slight issue.  In my variant, there are two kings (it's actually a king and a queen, but they function the same as a king regardless, including check).  The computer will willingly move his king into check, and the rules don't seem to prohibit this.  I have a feeling this is because the pieces cannot capture in my game, but they are supposed to be able to deliver check (I suspect this because the opponent will try to play a move where his king takes a piece defended by my king, and it freezes the other player, eventually causing him to lose on time).  Do you have an idea of how to fix this?