Herlock Sholmes:
I wonder, do you play backgammon (I don't very often) ... but here is a game which may rival chess in its popularity and its list of variants even though I think it has far less opportunities to be morphed. But still the traditional game prevails. Go is the same.

These days I play very little traditional chess as I do not have time to read as widely as some and to play at the higher level you need to or be quite gifted (which I am also am not). I, probably like you, enjoy playing variants where there is no great history or written material on the benefits of e2-e4. I enjoy playing in an even challenge and find this is the province of variants for me.

I believe the reason why traditional chess, backgammon, go and the like survive with very few rule changes is that they have already been proofed by the test of time. I do not know of one variant that takes less away from the traditional game than it adds. Maybe you would like to analyse a few examples to try to prove me wrong.

In conclusion, I agree there is an element of truth to what you say about the "boring" nature of traditional chess and I am sure this is more prevalent at the higher levels ... championships played where the majority of games, despite the clever play, end in draws in no great inspiration ... but when you look at the subtleties they are often quite astounding and beautiful ... way beyond my capabilities.. I am not convinced that a plethora of variants would lead to such revelations.

Herlock Sholmes: I like chess variant very much, but only on internet and in pub. Its very funny to play in pub bughouse or dice chess. Classical chess are like serious old professor, but I like him!

In Behemoth Chess, can the behemoth move in opposite directions on consecutive turns? Can the behemoth move in the same direction on consecutive turns?

Thad: random 4 squares...so anything is possible.

I thought that might have happened in my game,
Behemoth Chess (Thad vs. A663)

At first, the behemoth moved from its initial D4 square to H8 then right back to D4, but it wrapped around the board on its way there and then came across the board on the way back. Perhaps the notation needs to be adjusted for this?!

Thad: it started at H8 and stopped at D4 according to the previous move.
the rules mention it can hop from 1 side to the other as in sphere froglet.

Yes, I understand the way it moved and and the movement rules. I was saying that,
1. f3/h8
is ambiguous because the behemoth can reach H8 by two different routes (and take out different combinations of pieces on the way).

A draw in Behemoth Chess..... Behemoth Chess (coan.net vs. mangue)

Now technically, my opponent lost his king first... so I think I should have won! It took the Behemoth 1 extra move to take my king. Grrr....

coan.net: The rules clearly state that that's a draw.

Thad: I know (and I'm not really complaining to get it changed or anything) - but the rules do say "If the Behemoth destroys both kings at the same time, the game is a draw." - well it wasn't the same time, it was the square after.... same TURN, but not really the same time.

coan.net: You can make the same argument that if you capture your opponent's king and get destroyed by the Behemoth that you should win, since the capture takes place first, but that's not the way the rules are either.

Personally, I don't think Behemoth Chess is a good game. I would never chose to play it. I did play it once as part of a tournament with random game selection. I won't play it again. Maybe some casual players like it, but there are far better games to play.

Thad: Seriously? If I were to capture my opponents king, and then submit and the Behemoth took my king out, it would be a draw????

Actually I never play this game either... it's just part of a random tournament, so don't ever plan to play many more of these games... (not to mention that I'm not that good at chess...)

coan.net: That's funny, somthing must have changed. I hunted for draw examples, here for example: Behemoth Chess (Gror vs. Mal 4 Inara)
Seems the same type of move

What do you know, after all these years, something unclear
In Los Alamos chess, can a pawn convert to a Bishop?

rabbitoid: no, pawns promote to queen, rook or knight only. I have tested: it is correctly implemented here :)

29/7/2010 Superchess tournament. Place Voorhout, "De Speleweij" The Netherlands
18.30 Childrens tournament 20.00 General tournament See also www.superschaak.nl

January All Games over 1600

Starts Wednesday
Single game round robin 5 maximum per section, so the most games started will be four for you. 3 day time limit

RGroszkiewicz: If the Ice Age freezes a king, the player who is its owner loses the game. If both kings are frozen at the same time, the game is a draw.

RGroszkiewicz: it would appear that white keeps playing

I think Ice age will come after check ar mate. Its logical, Mate is end of game.
Ledové šachy (Pioneer54 vs. lukulus)

That mate occurred in White's 40th move. The Ice Age occurs after Black's 40th move.

I agree with lukulus that it would be more logical when the mate would be checked (and counted) first before the Ice Age occurs, although his example isn't a proof that it's actually handled this way. As far as I can see there is no such proof in the database. I looked at all games which end with a mate after Black's 20th (40th, 60th, ...) move, but all games I've found are by direct contact with the white King or by a Knight's move (see link list below). This is not a positive proof that Ice Age occurs first, because maybe no one yet dared to try to test the behaviour ;) The other positive proof would be a game that continues after a would-be-mate after Black's 40th move, but that is hard to find in the database because in such a game the move wouldn't even be marked as a check, so one would have to go through all games with at least 41, 61, etc. moves. So we should simply wait for the one with the inside knowledge: one short post by Fencer would be enough: "Mate" or "Ice Age"? :-)

20th move
Ronin - talen314
El Cid - Pioneer54
Nuno Reis - pauloaguia

40th move
Franklin - volor
yoyudax - asdf
Jaymom - chudu1980

60th move
diogenysos - basplund
Brainwave - Jatack

P.S.: Well, after looking at all those games once more, in each of them actually an Ice Age occured although it's already mate. Maybe that's an indication that Ice Age occurs first?

in RGroszkiewicz example....there was no check mate with the rook being moved to E1

Bwild: If White had played 40. Bd4 instead of 40. Bb4, then 40.- Re1 would have been mate unless Ice Age takes precedence. But even if it's not mate then it would have been a possbile move because the rook wouldn't freeze with the white Knight on f2 as a neighbor.

In my mind, ice age precedence is logical, given that "mate" is a shortcut to taking the king. If, at the end of move 20n an Ice Age occurs and means that white can no longer take the king, then the game would continue.

kleineme: I'd be much more inclined to ask the game's inventor (or leading players, if the inventor is not available), rather than basing anything on the actual implementation here at BK.  There are things here that could stand improvement.

I'm a variant lover but not an ice age player, so feel free to discount my opinion.  But I'd much rather see the rules of what constitutes "mate" remaining consistent throughout the game, no matter what the current move number happens to be.  Let a move be completed before an ice age occurs.

The "taking the king" argument leads one astray.  If you follow that "logic", a king could move into some checks, secure in the knowledge that an ice age was about to save him.  I'm sure we don't want that.

wetware:
I agree ice age should be after black's 40th move. If that is not the case there is an inconsistency between being black and white as it is definately after the white 40th move. Playing an unrated game following the moves of the game in question and varying at the 40th move would determine what actually happens on bk.

Justaminute: It shouldn't be too difficult to construct a game where black gives mate from a distance on move 20.

pedestrian: True,
happy to play it but I can't make or accept invites until I get below 50 games.

I can't tell about the specifics of Ice Age Chess and I agree that the fair way to tell would be to ask the inventor, but IMHO DarwinKoala has the right line of thought. A mate is not a mate if you can't actually take the king at the next move.

For an extreme example, consider a hypothetical variant where the queen is not allowed to move a single square (to make a king's move). You play 1.e4, 2.Bc4, 3.Qf3, 4.Qxf7. It would sound odd to claim that it is a mate because it would be a mate in orthochess, wouldn't it ?

As for the unwanted possibility of a king "moving into check", I think it is playing with words. If a king can't be taken at the next move, then its "moving into check" is just a potent optical illusion.

It is always possible to decide otherwise, but I think that in general variant design, playing up to the capture of the king should be the default.

DarwinKoala: At first I thought that enforcing the Ice Age before evaluating the position would be too big an advantage for White because he can mate on move 20, 40, 60 in a conventional way but Black cannot. But maybe this evens out a bit that Black has a serious advantage in always having the last move before the Ice Age.

Don't forget that forcing a capture of the king is not the idea... otherwise stalemate would be a win. We still need the king to be in check for a checkmate to be valid.

nabla:
I'm not sure your definition of checkmate is correct. Fide's website says:

The objective of each player is to place the opponent’s king ‘under attack’ in such a way that the opponent has no legal move. The player who achieves this goal is said to have ‘checkmated’ the opponent’s king and to have won the game. Leaving one’s own king under attack, exposing one’s own king to attack and also ’capturing’ the opponent’s king are not allowed. The opponent whose king has been checkmated has lost the game.

The question in ice age chess would be does the definition of legal move apply at the time of black's 40th or white's 41st? Clearly not an issue in standard chess as the board is the same. I would vote for on black's 40th for symmetry.

grenv & Justaminute: You are correct that the king must be attacked and that I forgot to tell about stalemate. If the stalemate rule is needed, what about "When you don't have any move that would not lose the king, you are allowed to pass your turn, and if the opponent doesn't capture your king immediately the game is a draw" ?

nabla:
I don't see any reason to rewrite the FIDE rules
If you don't have a legal move the game is over. Nothing to do with taking a king on the next move.
The rules also cover the point about moving your king to a square where it is under attack. Again the question is , is it defined as being under attack on bliack's 40th or whites 41st? I vote black's 40th

Justaminute: I think the rule is clear and doesn't need clarification.

The ice age event happens between blacks 40th move and white's 41st...

if the event means that white can move out of check (or simply isn't in check any more) then blacks 40th move is not checkmate.

Interpreting it the other way is simply misunderstanding that this is a different game than regular chess... just because the position *would be* checkmate in a regular game doesn't mean it is here.

grenv:
Which is correct if you assess the position at whites 41st move but not if you assess the position at black's 40th. As black never benefits from being saved by an ice age I don't support the argument that whitr should be able to.

Justaminute: That would seem to be an argument for how the ice age event goes into effect at all... but once you have the event you should treat it consistently.
Maybe the ice age event should happen every 39 moves instead of every 40 so that it alternates.

grenv: alternating ice ages would seem to even out the playing field

Justaminute: I don't see any reason to rewrite the FIDE rules.

Actually there is one. The FIDE rules are ambiguous when it comes to variants. When is a king "under attack" ? If I am playing my king in contact of the opponent's queen, but some extra rule forbids the queen to take my king (e.g. at that move my opponent is forced to move a knight), then is my king under attack or not ? If you would answer yes, I would argue that you are falling for an optical illusion.

Conversely, if my king is safe orthochess-wise, but can be captured through the way pieces are captured in that variant (for instance, in Atomic Chess, by an explosion), is my king under attack ?

nabla: as soon as your opponent makes his 1st move

Bwild:

nabla: You only need to alter the rules to the extent of creating the new game, superfluous amendments don’t add anything except the ambiguity that you seek to avoid. You couldn’t pay three check chess without changing the definition of how the game ends. There is no need to do so in loop chess though. The only clarification of the rules that is needed in ice age chess is the assessment of checkmate occurs at the end of move 40 or the start of move 41. There is no need to refine checkmate in this game.

Justaminute / Nabla: I believe that in Atomic chess you should be considered to be in check if a move of your opponents could blow up the king.... i think that is a mistake in the implementation... however it doesn't really matter or change the game too much.

In this case you're asking the wrong question. Checkmate occurs at the end of move 40 - However - the definition of checkmate is that the king cannot move out of check on his next move. Since the next move is move 41, the ice age event intervenes and must be taken into account...

I don't see how the interpretation could possibly be any other way unless it is explicit in the rules (which it isn't).

You can argue that it is a lop-sided game as a result if you like, but I don't think you can argue the interpretation;.

Justaminute: You are right, there are basically two ways to solve such questions.

1) Defining what is meant by check and checkmate in every new variant (even in Loop Chess, you will want to make clear that a ortho-checkmate from a distance can by parried by dropping a piece).

2) Going back to the axioms and work out what chess really means by check and checkmate, then keep those axioms as they are in every new variant bar some exceptions (three-check chess would be one).

I am not saying that 1) is stupid. Actually it is the way things are most often done. But even if you want every variant to include a (generally redundant) part about check and checkmate in its rules, it doesn't hurt to know that there is a default value given by 2).