Comments by jlennert

The variant you describe is listed on the site under the name Compromise Chess.

Now seeking playtesters for the second expansion. There's currently an announcement at the top of the Victory Point Games main page; instructions to apply are here.

Oh.  I guess I overlooked it because it has no moves shown.

I never thought it was supposed to be a handicapping system, I thought it
was supposed to be a system for creating an initial board position from
which a typical player would have equal chances of winning regardless of
which side he played.

So I am pointing out that:

1)  At best, this sytem merely provides MOTIVATION for creating such a
position.  That's kind of like adverising a "method for lifting heavy
objects" and then revealing that the method is to offer a higher wage to
employees who can lift more.  You aren't solving the problem, you're
hiring someone else to solve it for you; the actual problem still needs to
be solved by someone at some point.

2)  Although this method aligns the player's incentives with the goal in
an idealized case, there are many realistic cases in which the player can
actually gain a larger advantage by strategically UNbalancing the game,
rather than making it as balanced as possible.  So you need to carefully
consider your circumstances before employing it, even just as a motivator.

A game rule is not a collection of words, it's an abstract specification of how the game transitions between different states. People who are playing Chess according to rules written in English and people who are playing Chess according to equivalent rules written in another language are playing "the same game", regardless of the fact that different words are used to describe it.

By the same token, "pawns may move 2 spaces forward on their initial move" and "pawns may move 2 spaces forward when beginning a move from their second rank" are the exact same rule in the context of FIDE Chess, because "the rule" is actually just a specification of which game states can transition to which other game states, and the set of possible transitions is the same in both cases.

They are different rules in the context of some Chess variants because they no longer describe the same set of state transitions. When someone is inventing such a variant, it is reasonable and appropriate for them to choose whichever generalization of the rule is best for their variant, regardless of which exact words someone somewhere decided to use to describe the original rule.

Though game designers who hope eventually to release expansions for their games should definitely think about how their rules will ultimately generalize in order to avoid headaches down the road...

Thanks, Muller.  This is a neat little tool.

Could you go into a little more detail about how the columns work when some of the pieces are colorbound?  With two colorbound pieces, I get two columns in rep2.txt, which appear to be same-color and different-color, respectively.  But with 3 colorbound pieces, I get 4 columns, one of which is all zeroes (including its total board positions), and none of them are labeled.  (Also, none of them are identical, even when all 3 colorbound pieces are the same piece-type and owned by the same player...)

I did some experimenting with mismatched royal pieces.  Interesting result:  while it is commonly known that KNN v K is drawn, it appears that NK v K (that is, a single royal knight + commoner vs. king) is generally won!  (89% won with black to move, longest win 29 moves, if I'm reading these results correctly.)  I suppose that shows the value of sacrifice.

How difficult do you think it would be to modify this code to accommodate 'lame' leapers, bent riders, crooked riders, and/or pieces with only 2-fold symmetry?

The fact that you can't capture the king in FIDE chess is a *consequence* of the check rules, not a separate rule.  Any move that would give your opponent the opportunity to capture your king is illegal; the issue of whether you're allowed to make the capture if you had the opportunity therefore never comes up, but the easiest way to explain the concept of check in the first place is by reference to the hypothetical capture of the king.

So, to recap, the laws of chess do not allow you to make a move that leaves your king 'in check'.  If 'in check' means 'able to be captured by your opponent before YOUR next move', then when your opponent is about to get 2 consecutive moves, it would be illegal for you to make a move that results in a board position where your king could be captured within 2 opponent moves.  Thus, players would need to foresee the capture 2 moves in advance just to check whether a particular move was legal.

It would still not be possible to actually capture the king, because every possible series of legal moves would result in the king being checkmated (and thus trigger the end of the game) before such a capture actually occurred.  (Exactly as in FIDE Chess.)

On a related note, has anyone tried playing with the Avian Airforce from Ideal and Practical Values part 3? That army features WDD, FAA, and WFDDAA, and so should also be able to make long-range attacks on the back rank.

So you're suggesting that checking the enemy king with the first of your two moves would result in a stalemate?  Interesting, though it seems like that could be unsatisfying, and might cause a lot of draws.

The obvious generalization of the rules of check is that the king is in check if it could be captured before the owner's next move (which in a doublemove variant would often mean within 2 opposing moves), but this has a couple of issues:
1)  It is not always easy to tell when a piece could be captured within 2 moves, making it hard to determine when someone is in 'check'
2)  The force required to checkmate a king that can move twice consecutively is quite substantial (see Betza's commentary on Monster Chess here: http://www.chessvariants.org/d.betza/chessvar/muenster.html )

And thus, various alternate rules proliferate to attempt to solve these problems.

I invented a doublemove variant in high school (which I imagine has been duplicated by many other inventors both before and since) that required the two moves on a turn to be made with different pieces, and also stipulated that the second piece to move could not pass through the square that the first piece started on (thus, no instant revealed attacks).  This has the advantage that a king is in check in any given board position if and only if he would be in check under the FIDE rules, and the doublemove helps only a little bit in escaping check (since the king cannot move twice).  I don't know if that would be considered a 'true' doublemove variant, though, since no indivual piece can move twice during a turn.

My variant also has obvious generalizations to three or more moves per turn that probably play equally well.  I only ever played it once, though.

I suspect there's several concepts concealed in J�rg's [23].

One could be that squares differ only by their relative positions; for example, there's no square where you become immune to capture, or that can only be crossed by certain piece types, or whose occupation immediately wins the game.  Though this would be violated not only by the river and palace in Xiangqi, but also by piece promotion in FIDE and Shogi, which perhaps calls into question the validity of that criterion.

On the other hand, you can still make many kinds of 'terrain' just by altering the connections between squares; for example, you could have a 'wall' between squares (causing them to not be considered adjacent), or a 'portal' (that causes two otherwise distant squares to be considered adjacent), or a 'rotated' square (that turns forward movement into backwards movement, or orthogonal into diagonal, for example), all of which can be completely described purely as changes to the connections between squares.

So perhaps you want a rule something like 'the squares comprise a regular tesselation of the playing field'.

And possibly another requirement specifying the overall shape of the playing field (e.g. rectangular).

Side-Topics:
 - Chess variants on boards with semi-regular tesselations
 - Chess variants played on an arbitrary graph

The FIDE laws of Chess do not forbid threefold repetition; rather, law 10.10 allows either player to claim a draw in the event a threefold repetition occurs.

In the absence of such a rule, the game would presumably go on forever, with neither player willing to break the cycle. The threefold repetition rule is simply an observation of the fact that if both players find an endless loop preferable to other options, then they have both implicitly consented to a draw. It doesn't change whether any position is theoretically won, lost, or drawn, it just cuts short the infinite loop.

For the Crown has many unorthodox pieces, and is adding more with each expansion. However, material values are quite different than they would be in a FIDE-like context, due to differences in piece density, deployment (dropping) rules, and various other factors. And mate #s are completely irrelevant, since both players have the ability to bring new pieces into play as the game goes on, and therefore bare king endgames do not arise.

I have composed rules and recommended piece values for using the For the Crown pieces in a point-buy chess variant, which are available on the publisher's product page. I believe I have subjected these values to rather more rigorous analysis than George has used in this thread, but I still consider them to be educated guesses, at best; I haven't tried to get more precise than nearest-pawn, and it wouldn't surprise me if several were wrong, even by that loose standard.