files=11 ranks=11 promoZone=3 maxPromote=1 promoChoice=QF graphicsDir=http://www.chessvariants.com/membergraphics/MSelven-chess/ whitePrefix=w blackPrefix=b graphicsType=png lightShade=#FFFFE0 startShade=#808080 symmetry=mirror succession=1 prince:F:K:man:e2,g2 pawn::fmWfceFifmnD::a3-k3 camel::::c1,i1 cannon:O:::e1,g1 elephant::FA::a1,k1 knight:N:::b2,j2 bishop::::c2,i2 rook::::a2,k2 ship::[F?fqR]::d2,h2 gryphon::[F?fsR]:griffon: queen:::: king::KdU::f2

Tamerlane II This variant was a submission for the large-variant contest. It is the subject of this weeks interactive diagram.

This variant has some funny rules that required special attention. One was promotion: not only Pawns promote, but a Prince reaching last rank can optionally promote to Queen too. And a Ship can promote to Griffon in the last-rank corners. This was handled by defining Prince as first piece, and specifying only one promoting piece, with as only choices Prince and Queen. This invokes the normal promotion procedure for Princes, letting the user select from the legend table.

Pawn and Ship make use of the user-supplied JavaScript function WeirdPromotion. This automatically promotes these pieces when they reach their respective zones, as in this cases there is no promotion choice.

Another unusual feature of this variant is that, when checkmated, Kings can swapped with Princes,wherever these are located. To make the diagram indicate this possibility, the King was equipped with a universal-leaper move U. The modality 'x', which was already introduced on non-final legs of multi-leg moves to indicate relaying of powers, is now used for indicating such a piece swap with a friendly piece on final (or only) legs.

Adding a plain xU to the King moves would allow it to be swapped with any friendly piece, however. To single out the Princes, we declared the board to be zonal by providing a JavaScript function BadZone. This function tests the the target location for containing a piece of the same color as the mover, and declares the to-square invalid if a non-Prince if found.

Hi Joerg,

 

inventing chessvariants is silver (computer-aided) playtesting is gold ;) If I don‘t err the Essential Knight Rider is your creation and the problem, that occurs for this army is as old as the piece itself => already in the starting position, it has impact on the enemy‘s camp. When I discovered the chessvariants-site in 2002 your article Nachmahr was my favorite entry for a long time. I never played that game, but I examined it, because it offers a nice overview of several Knight Riders. In those days I saw already the problem that the Essential Knight Rider on g1 can take the Narrow Diagonal Crooked Knight on c8, the pawns on the third rank don‘t prevent that.

 

It‘s funny that this kind of crooked Knight Rider was invented last, it actually is the most logic Knight Rider. It is a strong piece, but not too strong, so you can combine it with pieces like the Rook or – like in this game – with the bishop. I‘m currently working on a chessvariant with crooked pieces and I plan to use combination of Boyscout an Essential Knight Rider as promoting piece. The funny thing is that the second Essential Knight Rider move and the third Boyscout move „overlap“.

 

There is another chessvariant that has to deal with a powerful Knight Rider, it‘s Ubi Ubi Chess. The solution Bodlaender found, was to shift the opponents f-pawn and the d-pawn one square ahead. You can probably introduce that special rule to save your brilliant idea.

 

The idea is really beautiful, the theme of this army is in my point of view, that the minor pieces are weakened. I like the introduction of the Knave, which was a topical piece in those days. The choice of the rook could be a bit more creative. You actually can weaken the rook and put an amazon on d1.

 

You pointed out, that the player has to make the decision, if he should develop the Knave or the Diamond on the natural knight development squares. One possibility to solve that problem could be, to place the Diamonds on one Wing and the Knaves on the other. I prefer the Knaves on the kings wing, because they can attack the opponents pawns in an e4-game. Otherwise the Knaves will almost always placed on c3 and f3 and the Diamonds have to evade to d2 and e2. On those squares they can‘t attack the opponents pawn, but they can at least protect the own pawns.

 

Greetings Chris ;D

Hi Zied!

Any update on when we might see alternate pawn pieces? Any chance they'll be available in the the first quarter of 2017?

In Ralph Betza's Pied Color Chess, all the pieces except Pawns are changed in their movement by the piing, unless they happen to have normal dark and light (eight)-square surrounding. In the Example the Rook on b1 starting to c2 can stop there or continue -b3-c4-d5-e6-f7-g8. In the coloration exampled there are no, zero, "normal" squares so far as adjacencies let alone two away and beyond. Watch what's beneath you!

I'd tentatively estimate the relative piece values in Modern Shatranj (current version) as: Pawn=1, Knight=3.5, Rook=5.5, King's fighting value (noting it cannot be traded)=4, General=4 (noting it can be traded or put what be 'in check', unlike a K, but I've judged their value in action to be similar enough), with the Elephant=3.125.

Kevin, you raise a good point about book sales, etc., but as for the "one year per setup" idea, I think Fischer's original plan was to avoid the opening theory discussion altogether.  If everyone studied one particular random setup for a year, I'll bet White's advantage would be exploited even moreso than it is in the standard setup.

With a random setup, determined just before the game starts, you can just look at a random position between two players and enjoy the actual battle of minds in that moment.  The match would be 100% performance-based, instead of being so preparation-based.

Since the 1820s backranks have been altered to thwart opening theory. Fischer was just as ignorant of chess history as Seirawan in the latter's re-introducing compounds of RN and BN to whatever he calls them in Seirawan Chess. Fischer's re-invention in the recent nineties of up to 960 set-ups led to also variants Slide-Shuffle and Deployment and Free Placement. Randomization of array is Mutator applicable to any CV. Instead at the same time of FRC, Ralph Betza proposed changing connectivity of the once-sancrosanct little 64-board. Besides Betza's two-ranks displacement, here are some other board possibilities: http://www.chessvariants.com/d.betza/chessvar/quake/quake.html.

There are also things like Transcendental, T_Chess where the two sides' initial positions do not have to match, and Chaos Chess in which pieces start dropped to other than only the nearest rank.

Altair is CV where "piece values are not a good indicator of one side's advantage in chess" to use V's current words, because most of the pieces for a move can also be dropped to empty square in rank nearby of the same color. Also they most of them can slide along their rank unimpeded. So if coming up with guide-values for stronger Mage and Lion and Diamond around 7, 5 and 4 respectively, good use of the board itself makes all the pieces closer to heuristic 3.8-4.2 each with only Pawns in some 2.x range.

Muller wrote up problem theme 3Q v. 7N in "Charge of Light Brigade." If you keep 8 Pawns, the 3 Queens versus 7 Knights may go to 3Q by already 8x10 any array, certainly by 10x10. Board used and Rules interact piece values, and cannot really be safely generalized even as to '<' or '>' for all cases; with special rules (or board) we can think of CV where even N>Q one on one!

For ex., make narrow stair step where Q can only occasionally go 3 or 2, but N leaps cross empty space and get values maybe N4 Q3 as convenient.

The game plays very well. The Minister and High Priestess both provide very interesting forks.

I thought the Bishops were placed oddly, though I know they were set to mimic Capablanca Chess. For such a large board, neither mine nor my opponent's were in play much (or at all). Potentially switching the Bishops and the High Priestess/Minister in the opening setup might fix this, as well as protect every pawn in the opening array and prevent white from procuring too strong of a center.

I favorited this game. Very inspiring short range piece combos and combat.

This game has a lot of great potential. I think the inventor had almost hit gold with the addition of the Mamra. In my opinion, the Mamra is just a little too powerful. Never have I, in good practice, opened up a game with 1. h3 or 1. h4. The fact that both myself and my opponent had opened up with pawn movements on the h file in order to free our Mamras is testament to the Mamra's power.

Play is balanced between advancing your Mamra towards the enemy King, maintaining your pawn line, and sac'ing every major piece you have in order to open up the enemy pawn line.

I think even a small change such as the prohibiting the Mamra to capture pawns would dynamically change the game for a much better play. Otherwise, White seems to have a huge advantage with such a powerful piece on the move.

This game looks very interesting and well thought. The idea of developping positional and strategy game by limiting the men scope to local action is a nice one. I'll surely try the ZOG file.

It would be good to add a typical game example that would show the interest.

Stephane Burkhart

Hello, vickalan,

I'm glad you brought this topic (infinite boards) on this website again. Infinity is something I fancy and there is reason to include it one way or the other in my own games. Anyway this is a difficult  concept to work with. I haven't properly understood the game but it seems to me that 2 experienced players will still do a a lot of draws. Also, why do the hawks start so much behind? Is there some justification related to the bishop move?  The game doesn't propose any innovative ideas besides of the infinite board, as the fairy pieces here are fairly well-known. There is an exception to that I do like a lot - the idea of the huygens. This piece is interesting lifting my first rating I post on this website to good.

Good luck, vickalan

On a standard 8x8 board, the knight and bishop are already very close in material value, so I'm not sure that this new rule would be welcomed by many players.  Perhaps the uncertainty of its value would make the game interesting to some.  Somewhere on the level of a rook or close to it?

I will add, however, that a "squire knight" would probably work very well on some of the large board variants to give knights more power and purpose.

White is going north and Black south as usual in the CV Upside Down Chess.

For OrthoChess problem by Lord Dunsany, solve this:

White is to play and mate in four moves. The position is one that could occur in actual play of F.I.D.E. Chess.

There is a fairy piece called the "Dragon", combining the movements of  the Knight and the Pawn. However the Pawn movements are in a forward direction only. If it has not moved yet, the Dragon gets a two-step forward movement possibility (with an associated vulnerability to an en passant capture).

Swap Chess allows serial swapping as a move along subsequent lines of attack.  Swap Chess has never been put up in Game Courier like Switching Chess.

Here is the only 3-handed circular chess so far.

The first move has to be illegal, so Black Pawn cannot on the first move take a White Pawn that has moved 1 P-a2.  Since it is legal move for Black, he cannot do so on move 1.

Another advanced pawn starting formation.

 

Squares increase in power.  Each time a piece leaves it, it leaves a trace, so a square can eventually confer Amazon power even to lowly Pawn when he arrives.

Pawns do not promote. The Pawns reaching promotion zone cause other pieces to promote and the Pawn leaves the board. The four-square occupation of King requires all four attacked for mate.

 A square that a main Middle board piece sits on has corresponding square in Above and Below boards. These locations (departure square) 'influence' whether a move can be considered or not. To make the move, it also must be legal within the Middle board. Sometimes the Above or Below two piece-types move their one- or two-square way, and other times they duplicate a Middle board movement. Rules may very well be interpretable (including moving opponent's piece) in all cases.

Player must keep a Ring of 3x3 made from the stones, and to win is to destroy opponent last Ring.  Stones move in 3x3s. This appeared first in Spektrum der Wissenschaft.

First, I wanted to say that my opponent handily outclassed me in our game.  I felt like every move of mine was a blunder. 

Aside from that heavy loss, I found the game very enjoyable.  I was definitely out of my element in this type of game, but the types of pieces really complimented each other and I see why this game gets a lot of correspondence and OTB traction.

I requested a game of this because I was very intrigued by the mix of pieces, though I think the game was shorted by it's need for rule clarifications.

A few things that I found only through research:
- The movement of the Nahbi.  The diagonal movements of the Nahbi do not change direction.  Thus, a Nahbi moves two spaces diagonally in the same direction, then one square in any orthogonal direction, in that order.
- Castling.  The correlation to FIDE chess is that it moves 2 squares left or right, not that the king ends in the same board position as in FIDE.  This was verified by downloading an external program (Zillions of Games) and loading the rules the inventor programmed.  

Once I found out how the Nahbi moved, I quite enjoyed the piece.  The non capturing move increases the mobility, while limiting it to being a sliding piece (instead of jumping) ensured that it wasn't too powerful.  I'd love to see it in other variants.

The Archer is a very good defensive unit and I feel is quite enough of a force to protect the king.  The Alfil, however, was useless.  In a 36 move game, neither players moved their Alfils and only one played a role in piece protection.  Limiting them to one side of the equator gives it 7 squares to protect, making them MUCH weaker than a pawn that has already crossed the equator.  Had the game continued, I would have been happy to exchange both of mine for a crossed pawn each.  If the piece is necessary to the game, I'd recommend removing the limit of remaining on one side of the equator only.

I did like the limit on the queen crossing the equator.  Seemed very fitting to make it a "short range" piece.

Yes Charles, I think it would be fine to drop this (he asks advice on this in red). "sidewaysmost, 'Halfcamel', 'skewed Dabbabah', 'Colourbound analogue' and 'river-straddling zigzag' are turgid and off-putting without any of Ralph's deadend tongue in cheek. However other CVs that get deleted also lose the scathing review.

I really like the mix of pieces added to the game.  The setup positioning of the Lions brings them right into the game early and the Unicorn is a very instrumental piece to the game.  It is very challenging to use and to guard against.

Neither my opponent nor myself made any moves with the Queen nor the Chancellor, which seem like very important pieces to use.  I am not sure if that is a regular occurance or not.  

The board is large, but not too large - big enough to encourage use of the Unicorn.

Wow, this game is quite a gem.  The piece combinations are perfect - some long range, some short range, but nothing too over powered.  It tends to be a slower paced game (our game was 70+ moves), but it adds a lot of depth.  

Two different types of pawns and 3 promotion potentials, with a possibility of getting a second king.  The kings, are also valuable pieces in the fight.  Possibly the strongest piece in the game if you can keep them out of check.  Recruiting is a very unique style of play, providing strategy that I haven't seen before.  In my opinion, by far better than the pocketing method of Shogi.

Another aspect that I found great was due to the smaller number of pawns, your "line" was maintained by your minor pieces.  Every move and every capture was meaningful in this way.  It felt like an actual battle instead of a game.  Very much so one of the best games I've ever played.

I definitely favorited this one.

Are you talking about victory by "allowing" perpetual flight of the opponent's final Queen? That is not the same as eliminating or subjugating a royal piece, which is the real object of a Chess variant. If it was necessary for that to be ruled a victory condition due to the mix of piece types in play, then the game is not really perfect.

Besides this, when any piece may ultimately ascend to royalty, the paradox is then whether the piece type named as "royal" is "really royal". The problem with naming a game which throws up this paradox as a "Chess variant" is that it then has no real royal piece, and Chess is defined as having a set of piece types which are royal and another set which, and any promotion to royalty must be a privileged promotion open only to certain piece types. Once again, if you were so strict about what the rules were to be like that you made yourself need to do this, then the game is not really perfect.

In summary, the game, although interesting, is not really perfect nor really a Chess variant.

Merging Chinese chess with Western chess was a very ambitious thing to do (altering two orthodox traditions) but I think you've succeeded! I like how you took the plain round disks and replaced them with chess pieces that are easier to discrimate. Good work on this interesting variant!
 

I've heard of non-edge variants of chess, but I hadn't read this specific page until just recently.  The game seems interesting and might eliminate the usual "going for the center in the opening" strategy.  Still, I can't help but wonder if the king might be tough to mate if there are no right and left edges.  Can a knight, bishop and king mate the lone opponent king?

Maybe they should make a restriction on the king - he is restricted to the usual board edges perhaps?

Two minor points:

A) The "Dababbaphant" is more commonly known as an "Alibaba.

B) The picket comes from Tamerlane Chess, not Courier Chess.

I'm facing a problem: I want to open a game in which it is my move. Immediately I get an error saying I can't drop a pawn on a file where I already have a pawn.

Yes, I do already know that I can't drop a pawn on a file where I already have a pawn. Especially when I haven't even made any move.

That makes sense, very interesting.  It would require some pretty deep thinking, even for just the next move or two, if all three of those pieces are interacting.  I'll have to try this sometime.

This looks like an interesting game, and I like many aspects of it - including its large size, good blend of traditional and new pieces, and clean crisp graphics. They work together well to create an interesting and appealing game.

I was wondering what it would take to play this engine-vs-engine.

The first thing I noticed is that CVPs page on ChessV brings up an error. Is this related to the recent server move?

I've also read that ChessV has a scripting option, which might allow custom variants to be entered and played. Is this game (Chess and a half) within the possibility to enter as a script? I've never tried anything like that, but I'm always willing to try new things.

Lastly, I know that custom variants can be entered to Fairy-Max. Does anyone know off-hand if this variant is within the size limit of Fairy-Max?

With a little bit of work, I MIGHT be able to get an engine-vs-engine game going of this variant. That would be really awesome. Why play myself, if I can let an engine do the work???

Chess 2 is a fantastic variant that really goes off the deep end in how it changes chess yet still retains that familiar chess feel. It's a great shame that it virtually has no playerbase. It pushes chess to a more gamer and esports oriented audience, in my opinion. Some have complained about the midline rule and duelling mechanics ruining classic chess endgames and adding an unwanted element of chance respectively - I say that on the other hand, midline makes endgames more exciting as moving your king to the midline is the endgame, and makes the king's activity in the game much more apparent; likewise, duelling is what keeps the balance of Chess 2 intact. The armies are supposed to be strong and weak against other armies, that way a metagame eventually forms.

Sirlin's site has since moved domains, and as a result the print-and-play version of the game has been obfuscated. However, I'd like to leave a link to a new version of the print and play that is still being updated:

https://drive.google.com/file/d/0B9qCB9zFQM1neHVMY3pUanh5eXc

And for one without backgrounds: https://drive.google.com/file/d/0B9qCB9zFQM1nOUcxLXVydWI4d3c

The text has been for the most part lifted from the old print and play, but there's a number of new things that I've added, such as:

• Updated diagrams - makes memorising the movements of the pieces a little less confusing;
• Rules for OTB play - just basic stuff for tournament play;
• CHESS 2 NOTATION. No form of algebraic notation has been configured for Chess 2, until now. I've devised (what I believe to be) the simplest and most effective way to record Chess 2 games while still respecting the integrity of regular chess notation.
• Multiple conversations that I had between various frequent players and beta testers.

For anyone who blows on by this page, I hope you'll take a look at it (if you're interested). If you're wanting to give feedback, you can always find me on chess.com or on lichess.

Hi.

I always enjoy new chess variants (especially as, as a composer, I've been occasionally making compositions with some feeric conditions, mostly for SPGs), so as soon as I read something about switch side chain chess on chessbase site, I DLed the android app to test it :). Here are my thoughts so far :

It's definitely original and one can clearly see the interest for AI given, even though chain detection is very easy to code, evaluating the positions is probably much more difficult to code with that possibility to switch sides (although it's obvious that when one side has the possibility to create a chain, it's a tremendous advantage - and white definitely seems to have a big edge with the current rules).

About the feeling and enjoyment of playing this :it reminds a lot of loser's chess (giveaway chess). Despite the fact that loser's chess is at the contrary veryyy AI friendly (don't know if some coders bothered solving it, but it's probably possible). You can lose extremely fast in the opening, but it is somewhat interesting to see how to play around these fast losses.

About the usefulness for chess composition : can be interesting for SPGs (shortest proof games) and retro analysis for sure. Not so much for mates/helped mates/inversed mates etc since chains require the presence of too much material.

About the software : wondered who you asked to code this.. It's passably aesthetic and the UI is ok, but the AI is inexistent.. I ve never seen it ever do a switch, and obviously not work around them either. And even when playing normal chess he is atrocious. That's the main reason for my average evaluation.

About possible changes to prevent very quick games, and give it a feel closer to chess rather than loser's chess : limiting the number of successive switches depending on the move you're at seems unnecessarily complicated. You could for instance consider a chain that involves a pawn still on its starting square as non valid. That would be a big change for sure, but keep it simple and interesting.

 

To finish, my fastest game so far against that weak program, as black :

1.e3 b6

2.Qf3 Bb7

3.Qxb7?! c6

4.Qxa8?? Qc8 (SB)

5.Qxb8 Kd8 (SW) (SB)

6.Ba6 d6 (SW) (SB)

7.Qxc8#

 

I'm not sure if it exists already as a modest proposal, but I like the creativity of the promotion rule (and simplicity of the general idea).  Trying to "aim" pawns toward the central files for a queen sounds interesting.  My only concern would be if an obvious advantage for either side occurs due to some open files very early on in the game.

One of the few examples of variants that are actually better than the original. 

Some people take a normal chess game, add a piece that combines the abilities of a knight and a Bishop, and already call it a new variant. This game, however, is a complete reinvention of its ancient predecessor. Many additional rules have made this game much more enjoyable, and have given it a completely new feeling. It actually feels really realistic; you can almost see the formations of hoplites rolling onto each other, pushing each other back, and finally forcing the losing party to retreat. But be careful not to advance too far, otherwise it might happen that a few swift skirmishers come charging from the other side of the board and fall into the flanks of your formations. And isolated soldiers have to take great care that they don't get simply overwhelmed and crushed in between their enemies. 

This is not just some of those minor variations. This game is just as elaborate, just as complex, and just as much fun as original  chess itself. Try it at least twice and see. 

I want to play with someone! :) 

I rate Berolina Chess as below Excellent since I somewhat dislike that pawns open files so easily, and that they can more easily become passed (plus Berolina pawns continually force the mind of an orthodox chess player to adjust at every stage of his calculations). The pawn structures that often result, in spite of not being clearly weak, also look ugly to the orthodox mind. On the bright side, such features (the merits of which can be debated) do attract a lot of variant players due to their novelty, in fundamentally shifting away from the foundation of standard pawns that is retained in so many variants.

As for chess, my estimates for the piece values would be: P=1; N=3.49; B=3.5; R=5.5; Q=10 and a fighting value of K=4 (though naturally it cannot be traded).

Here's an experiment 10x8 CV that uses Berolina Pawns also:

https://www.chessvariants.com/play/gamma2-chess

I like the concept of multi-player chess variants (or ones in which two players each control more than one army, which is how this game is currently played on Game Courier), and perhaps there ought to be more of these. The problem of how to handle the surviving pieces of an army whose king has been captured (if not mated) may be a bit tricky to do in a reasonable way (i.e. in order to make it worthwhile for good players continuing to play out such a game further, at least at times). I think this particular variant seems to solve that problem well enough - if nothing else the variant is well tested and continues to be played, I gather!

My tentative estimates for the piece values in this variant would be: P=1; N=2.5; B=3.25; R=5.75; Q=10 and the fighting value of a K=1.6 (if the first of one team's kings is captured, ostensibly winning an exchange value of 1.6, add to this exchange value a periodically recalculated bonus of [sum of the value of the pieces and pawns in the remainder of that king's army, for as long as any of it remains on the board]x0.8 for virtually immobilizing the remainder of that army, with full value awarded for any virtually immobilized pieces that are subsequently captured); note that naturally the second of a team's kings cannot be allowed to be captured without the loss of the game.

In spite of what I see as the drawbacks of this variant (unprotected pawn for each side in setup, rectangular board [though allowing smothered and back rank mates still], bishops clearly stronger than knights, the fact the chancellors might be developed symmetrically and traded in short order sometimes), this was a good try historically to cut down on draws and opening theory.

On this particular variant's board dimensions of 10x8, as compared to 8x8, IMHO the archbishops would seem to come closer in value to chancellors (though not queens), though I personally have lingering doubts about archbishops being quite as good by comparison on 8x8 or 10x10 boards, any computer studies aside. IMHO, the bishop component of an archbishop would seem to have a number of extra potential good squares near the centre (or in range of the enemy camp) on a 10x8 board, without the rook component of a chancellor benefitting as much as often in return (unlike would be the case on a 10x10 board). On a 10x8 board the knight component of an archbishop would seem to have a number of extra potential good squares near the centre (or the enemy camp) for local scope, balancing the benefit received by the rook component of a queen on such an empty larger board than 8x8.

My tentative estimates for the piece values in this variant would be: P=1; N=3.5 approx.; B=3.75; R=5.5; A=8.25; C=10; Q=10.25 and the fighting value of the K=3.2 (though it naturally cannot be traded).

edit: Here's a 10x8 CV that uses 2 powerful and unusual pieces, besides the chess army and Berolina pawns:

https://www.chessvariants.com/play/gamma2-chess

Also, here's a 10x8 variant that uses Frogs besides the chess army:

https://www.chessvariants.com/rules/frog-chess

A link to a published preset for a circular Capablanca Chess style variant:

Circular Capa Chess

A popular variant on Game Courier currently, Cetran 2 has an interesting combination of pieces in whatever starting position is selected (by man and/or machine), many of them powerful, with the superb Sissa piece undoubtedly being the star of the show.

My tentative values for the pieces in this variant would be: P=1; N=3.5; R=5.5; DH=6; A=8; C=10; Q=10; S=10.33 approximately and the fighting value of K=4 (though naturally it cannot be traded), as given by a number of world class chess players historically, re: chess itself.

In spite of what I see as the drawbacks of this variant (bishops clearly stronger than knights, marshalls able to be traded quickly if developed symmetrically, complex pawn promotion rules that I don't quite like), the game uses a square (rather than rectangular) board and there are no unprotected pawns in the setup, which are arguably improvements over Capablanca chess (although that game's setup allows for smothered and back rank mates, arguably good features to have). The fact that the rooks protect each other, so that there is no need for castling, is both a plus and a minus in my view (as is the fact the player's armies ranks have many empty squares in the setup - otherwise there could be 30 pieces per side, perhaps, as I tried in my own Sac Chess variant, which is a lot of pieces).

My tentative estimates for the piece values in this variant would be: P=1; N=3; B=3.5; R=5.5; C=7.5; M=9.5; Q=10 and the fighting value of the K=2.5 approximately (though naturally it cannot be traded). Note that I rate a N significantly lower on a 10x10 board than on a 8x8, 9x8 or 10x8 board (where I estimate N roughly=3.5 in all cases) as the many extra excellent central squares available to a N on a 10x10 board are IMHO way more than offset by the rather large size of the board, which makes it harder for a N to cross from one side of the board to the opposite one. Also note that on the four board sizes I've mentioned, I've kept R=5.5 as a constant value, changing the value of a B as I felt appropriate for a particular board size(s), in relation to the value of a R.

Here's an early CV invention of mine, a modified version of Grand Chess, which some may or may not like due to the positioning of the bishops in the setup, alone:

https://www.chessvariants.com/play/chess-1010

Two queen per side makes for a rich variant, though perhaps my bias as an orthodox chess player goes against it (in that game a king starts with one queen, or wife, though it's possible he may become a bigamist later in the game). My more real concern with this variant is that after a very early bishop's conversion by White, both Black pawns that are guarded in the setup only by the rooks can come under a double attack.

For Black to defend or counterattack against this possibility (also a similar story for White, if he starts less aggressively [perhaps]) seems to limit his choice of responses for tactical reasons (i.e. to avoid losing at least a pawn for more or less nothing, perhaps), and that may make the opening possibilities in the early stages less rich, at least for Black.

However, Shogi suffers from a certain lack of variety in the early stages, as far as the best moves go, and yet it is a classic. All in all, I think Hexajedrez promises to be a successful variant, if it were tested more, by skilled players especially. I certainly like that there are significantly more pawns in this variant than in McCooey's Hexagonal Chess (actually the same number as in Glinski's Hexagonal Chess, which uses different pawn rules).

For what it's worth, decades ago I saw the following piece values for Glinski's, which ought to also be applicable to this variant (as well as McCooey's): P=1; B=3; N=4; R=5; Q=9. I would add that I tentatively estimate the fighting value of K=4 approximately (though naturally it cannot be traded).

Cool variant. The extra basic rules are slightly complex, but still, cool variant.

It may be worth giving here the relative piece values for Crazyhouse that I once saw on someone's blog; these values just might actually be of use in assessing the [tactical] usefulness of pieces in games of Hostage Chess, in a general way, too: P=2; B=3; N=3.5; R=4; Q=6.

Excellent concept. One can quibble about the class certain pieces ought to be in, and the extra basic rules are slightly complex, but cool variant.

My tentative estimates for the piece values of this variant are: Class 1: P=1; Class 2: N=3.5, B=3.5; Class 3: R=5.5, NN=5.75, SB=6; Class 4: C=7.5, SR=8; Class 5: Q=10, M=10, SC=10, CC=10.25; Class 6: MM=12.25, SM=12.5, SCC=12.75; Class 7: A=14.5, SMM=14.75; Class 8: AA=16.75. Note that I tend to agree with various world class chess players who historically gave the fighting value of K=4 for on an 8x8 board. I also tend to agree with chess authorities who in the past valued a B microscopically better than a N on average, so perhaps a better value for a N (or the N component portion of any of the appropriate compound pieces listed above) might be, say, 3.49, to reflect this belief, though I prefer not to use ugly fractions when thinking of most piece exchange value calculations that might arise.

The interesting bishop's conversion rule makes this variant tricky to handle in the opening stages. On a 9x8 board, bishops are only clearly slightly better than knights, the development of which can also be tricky to decide on. The extra queen per side make this a variant rich in possibilities.

My tentative estimates for the piece values of this variant would be: P=1; N=3.5 approx.; B=3.75; R=5.5; Q=10.25 and the fighting value of K=3.5 approximately (though naturally it cannot be traded). Note that a N has slightly less excellent central squares on an empty 9x8 board compared to on a 10x8 board (in Capablanca Chess I rate also rate a N as worth 3.5 approx., but actually a little less than on 9x8 when not rounding to the nearest 0.25), but the 9x8 board being somewhat smaller seems to at the least offset this IMHO, as a N can have a slightly easier time getting from one extreme flank to the other.

This variant is berserkly sharp, as befitting of the name, and a stronger player could easily suffer an upset loss if he is at all having an off day. The rectangular, rather than square, board cannot be helped, but it is clearly justified.

My tentative estimates for the piece values of this variant would be: P=1; B=3; N=3.5; R=5.5; Q=9.5 and the fighting value of K=3 approximately (though naturally it cannot be traded).

Excellent concept, as somewhat borrowed from the original French variant. I'd suggest an alternative deck of cards, the same except for more child-friendly illustrations, might be used be used for when a child(ren) is playing the game.

Dr Muller, you mention the bare king rule as used by the Nihon Chu Shogi Renmei, but I have to wonder if your computer analysis has revealed what pieces singly or in combination are sufficient to force or at least deliver checkmate on a bare king in chu shogi.

www.naviadratp.net no longer working

A variant with an interesting mix of past and present. It seems possible and desirable for White's (or sometimes Black's) central pawns to strive to both advance to the squares on the fourth rank relatively early in many cases, much as in chess. To me that's a healthy sign for a two army square or rectangular board variant with an even number of both files and ranks, as far as the richness and logic of the opening phase of a typical game of it might go.

As far as this variant's 12x8 board goes, in the old days such would be fine in someone's home on a table, but nowadays if it were to be played over-the-board in a tournament hall (as in a chess tournament) its being 12 squares wide would naturally count against it as far as having physical boards with squares (and thus pieces) that weren't somewhat small in size (otherwise the boards would often take up too much room on a table in a tournament hall). Luckily this isn't much of a consideration for internet contests involving a variant with this one's otherwise unwieldy board shape. Another concern would be that the game might take too many moves to play on average, say compared to chess, but I'd suppose it wouldn't be as bad as in the case of the original 12x8 Courier Chess variant, with its relative lack of more powerful piece types such as the modern queen.

Here's 3 different 12x8 CVs with a quirk or two:

https://www.chessvariants.com/rules/wide-chess

https://www.chessvariants.com/play/champagne-chess

https://www.chessvariants.com/play/parity-chess

How can an opponent intercept a pass? Is a pass considered a move so that the other player gets a move to try to intercept? Or does the puck move at a limited speed? 

IMO One of the better contemporary variants out there, featuring a great mashup of fairy pieces old and new. Where s-chess allows for a far more sly strategy concerning the pieces in hand, musketeer chess respects the integrity of chess’ perfect information by having players pre-determine their drops. My only critique would be my concern towards the inevitability of the piece roster expanding. Will the future second and third series pieces be welcomed updates, or will they sour the game as it stands? I can’t really say. As a commercial variant though, it is fair to say that musketeer chess, and the ‘Modern Chess Variants’ project in general, is highly ambitious.

I was approached by Dr. Haddad to write an introductory article to musketeer chess. It details my experiences and developed theories playing the game, plus some basic endgames and even an interview with the creator himself. Check it out, if you’d like! https://www.chess.com/blog/Ebinola/an-introduction-to-musketeer-chess 

A cool looking game!

I'm now wondering if it's feasible to even do a non-rules enforcing preset for 2 player Bughouse on Game Courier (i.e. it would be two players controlling an army on each of two boards within a diagram, but only one clock per player unlike over the board bughouse even when played by two), as the two sides would each have a White and a Black army in front of them on their left or right side respectively. [edit: perhaps merely being restricted to just one clock per side would make such a bughouse variant preset on Game Courier unworkable, as a player might just move on one board only, when in trouble on the other board.]

This was the first chess variant I'd ever heard of, way back in elementary school around 1970. After trying it a few times I disliked a game that would rely heavily on giving away stuff to the opponent in order to win. Looking at the variant's webpage nowadays, I can see this variant has depth, in spite of my still not liking it much as far as the thought of playing it myself. The extensive opening theory that apparently one needs to know to survive (in any sense) against strong losing chess players looks daunting, and I'm a bit disappointed that the traditional and obvious chess centre pawn moves 1.e4 and 1.d4 are thought to lose for White in this variant. So, not my cup of tea (at least at present) but I can see how this variant and its basic concept might attract many other people to it.

I have sampled a few games of hiashatar on an 8x10 board and have concluded that it results in much too constricted positions, even if pieces come into contact sooner and the balance of open squares and number of pieces matches chess.  I have seen hia chess on CVP and would like to know if others have experience of the hia on a smaller board and have evaluated its suitability for a board of fewer ranks.  I used to think hiashatar seemed too large, but now I am unsure.  I would welcome opinions or accounts of player experiences.

An excellent concept!

Inspired by it, I can suggest many Chess With Different Armies-like variants that, to my taste, might be especially interesting to try out sometime:

That would be with the Different Armies idea used to make any number of versions of the following variants 1) 9x8 Symmetric Chess; 2) 10x8 Janus or Capablanca Chess; 3) any number of 10x10 variants, such as Grand or Sac Chess; 4) 4x16 or 5x16 Circular Chess variants; 5) Glinski's, Symmetric Glinski's, McCooeye's or Hexajedrez (91 cell Hexagonal Chess variants); 6) 4-Way Chess; 7) Crazyhouse, Chessgi or Hostage Chess; 8) Pocket Mutation Chess; 9) Backlash; 10) Marsailles or Progression Chess.

Is this a retail game, or a home variant?

This looks like a cool variant! It's too bad that I find the existing preset for it to be unsatisfying.

Shatranj is a cool variant mainly for its historic value, IMO. It's awkward, weak ferz and (especially) alfil (or elephant) pieces make it somewhat frustrating to play for many a modern player, again IMO. The present variant, Shatranji, removes some of this frustration, as dropping either of these weak pieces after they are captured allows the (now not necessarily permanent) binding of them to become less of an issue. However I find the elephant piece still awkward to use, while it is still on the board, in Shatranji, owing to its double binding. I'm wondering if a 'Modern Shatranji' version of Joe Joyce's Modern Shatranj variant (i.e. crossing it with Chessgi-like drops), with Joe's use of guards and modern elephants, rather than ferz' and alfils, might prove at least as good in practice as Shatranji.

[edit: Here's my tentative estimates of the piece values for this variant: E=2.06; P=2; F=2.25; N=3.5; R=4.]

Just a small update on the post by Jaymes. Taking the picture shown in the article for the starting position, the left hand side is the Queens side and the right hand side is the Kings side. The Kings and Queens should be on the movable levels next to the Rooks (or Castles). The back rank on the top and bottom levels should have the Knights at each side with the two Bishops on the centre ranks. At least, this is the setup shown in the pamphlet I got with my official Star Trek Tridimensional Chess Set almost 30 years ago.

This hexagonal variant looks intriguing, and I'm a bit surprised that so far it has received no tests on Game Courier (presumably it did by now on ZoG). The pattern of the board (vertical hex alignment, rather than horizontal) and the peculiar way the pawns move might prove a refreshing change from McCooey's or Glinski's variants. My biggest concern is that a well played game might take a relatively large of moves on average.

edit: when in doubt, see this page's Grand Hexachess link for a different wording of rules that are clearly meant to be the same.

This is a cool game to play, though I myself had some slight difficulty with possible ambiguity to the wording of certain rules, as put forward on this page. One case I solved by looking at an earlier comment about this page that George made, in reply to someone's question about a rule. Other than that, the different colouring scheme of various ranks, and the purpose to that, is one nifty aspect of this game.

Higher dimensional chess variants are often noble experiments that never seem destined to gain much popularity. On its own merits this 3D one looks noble enough, in attempting to tame the chance of the players facing a large number of candidate moves at each stage of a game, in regard to their calculations. Is a 4D version of Shatranj in the works, or out there somwhere? That might be nifty to see, too. [edit: I'd forgot about the 4D Shatranj-like variant Chess on Two Boards by the same inventor, though it's stated on that game's page that it is a 'broken' game.]

This game reminds me of an old chessboard puzzle involving the placing of a number of queens, to solve a certain task, but of course Amazons is something even more complex, in that it is a full-fledged game. It also seems almost simple at first sight, deceptively so.

Cool concept!

Another cool idea by Fergus.

Interesting game. In my limited experience with it the knightriders seem rather dangerous pieces. I'm not sure I like the detailed promotion rules, but maybe it's a matter of taste.

Here's an experimental 10x8 CV that uses unusual type of 'pawns' also:

https://www.chessvariants.com/play/compound-chess

This seems like a great game, where the action might normally develop slower than in Cavalier Chess, but it's worth it.

Here's another variant that includes Nightriders on a large board:

https://www.chessvariants.com/rules/wide-nightrider-chess

The apothecary games may have a somewhat steep learning curve, but it seems it's well worth the trouble, based on my limited experience.

The apothecary games may have a somewhat steep learning curve, but it seems it's well worth the trouble, based on my limited experience.

This game kind of reminds me of the even more non-violent principle that inspired Fergus Duniho's Clockwork Orange Chess.

A cool idea for a variant. It takes some time to discover various strategies that can be employed by the players with the stated rules.

[edit: My tentative estimates for the piece values are as follows: Capturing pieces: P=2; B=3; N=3.5; R=4 and Q=6 (same values as I gave for in Crazyhouse); Non-capturing pieces: P=1.25; B=1.5; N=1.75; R=2 and Q=3 (computed using x0.5 penalty for non-capturing movements - note a pawn is thus slightly less affected in its value decrease).]

A fresh idea for a variant that at first made me wonder if the game was truly playable. The answer is a resounding yes!

Several interesting piece types in this game. Can well-played games of it be reasonably short on average? Time will tell, but I suspect most such games won't go past 100 full moves, good for such a large board.

This looks like a really interesting game. The movement rules certainly speed up play on a large board.

A poorish game by modern standards, especially due to the alfil pieces, but modern chess is indebted to this historic early version of it.

A poorish game by modern standards, especially due to the alfil pieces, but modern chess is indebted to this historic early version of it.

Here's a 10x10 Shatranj-style variant with 4 Kings per side:

4 Kings Quasi-Shatranj

You've just got to love a variant that's really big, even if you don't want to play it much. Now that there's a rules-enforcing preset courtesy of Nick, the chance of playing game(s) of it went up for me.

You've just got to love a variant that's really big, even if you don't want to play it much. Now that there's a rules-enforcing preset courtesy of Nick, the chance of playing game(s) of it went up for me.

Though this variant may never be as popular as its close cousin (and better known variant) Crazyhouse, it is equally excellent on its own merits.

A big board game where the inventor doubles-down on the 6 chess piece types, but the fast pawns rule adds an interesting twist to speed things up a bit.

A great historic variant. Games may last a large number of moves, but the slow pace may prove heavenly for some players.

In interesting variant that has a board geometry somewhat like that of Circular Chess.

An interesting concept to extend Alice Chess' idea. I'm inclined to think (but lack the mathematical skill to prove) that the connection between the three boards is a 4D one in disguise - bishops, if they were present, can travel paths one board at a time back onto their original starting board, arriving there on square(s) (e.g. their exact start point) that they wouldn't be able to reach if the variant was truly 3D (like Raumschach is).

An interesting concept for a variant! On a Canadian chess message board a long time ago, someone asked if there could possibly be a variant with quite a number of impassable squares here and there in the middle of the board, and I assumed the idea infeasible, not imagining that a player might be able to move said obstacles around!

A fine variation on the idea of Grand Chess.

Shatranj meets a 10x10 board in style!

Here's a 10x10 Shatranj-style variant with 4 Kings per side:

4 Kings Quasi-Shatranj

Another nice Shatranj variant from Joe, this time on 10x8.

I'd tentatively estimate the piece values as P=1; N=3.38(=3.5 approx.); E=Y=2.695(=2.75 approx.); Guard(approx.=K's fighting value)=3.2; HP=MI=7.075(=7 approx.); R=5.5.

This game plays especially well with its 3-mover variant rules.

This variant is clearly one of the more original chess variants, and which has been around for quite a while.

A historic and very playable variant. What's not to love?

This game is really sweet for a quite large (12x12) variant, and as advertised it has a small learning curve. Lots of fun!