Does this mean I can create an Interactive Diagram for Chess but the King in check cannot travel?

Edit: It does!

I added a feature to make it easier to debug or copy an Interactive Diagram: there now is a button 'Source Code' under the legend (which you open by clicking the 'here' link twice). When you press that, the definition of the Diagram is displayed below it.

Does this mean I can create an Interactive Diagram for Chess but the King in check cannot travel?

Not sure what the 'this' in your message refers to.

It is a good idea to publish these pictograms. I confirm that the Chu Shogi applet is a success

I fixed something that was broken. The n modifier on a W or F step, which is not useful in the normal meaning of non-jumping, was 'overloaded', and supposed to indicate that the step 'leaves behind' an e.p. square on the square it came from. This way the path of lame leapers explicitly specified as a multi-leg move could precisely indicate whether and where the piece could be e.p. captured.

The Diagram furthermore applies the rule that royals can be e.p. captured by normal capture (c) moves; the capturing piece does not need to have an explicit e mode for that, like it would need to e.p. capture non-royal pieces. This is for instance how the ban on castling out of or through check works: the castling creates e.p. squares on the King's origin, and the square it passes through. So that castling through check exposes the King to e.p. capture, and would thus be illegal.

I used this to make a Diagram for Caissa Brittania, where the royal Queen cannot move through check (nQ). Each step in the slide then created an e.p. square. But also on the origin, which would forbid moving out of check. But in Caissa Brittania moving out of check is allowed, so I suppressed generation of an e.p. square on the origin, and only left it for later steps in the slide.

This, however, broke the use of n on non-sliding W or F, where it became a complete no-op. I now fixed this. So nK would now be a King that cannot move out of check without getting e.p. captured, but moving a royal nQ out of check would still be legal.

[Edit] I am now starting to doubt the wisdom of this (irregularity-introducing) convention. If nQ would also create an e.p. square on the origin, one could still write [K?nQ] (= KyafnK) when this is not desired. OTOH, with the convention you would need [nK?nQ] (= nKnyafnK) for a royal Queen that cannot move out of check. [K?Q] is after all just synonymous for Q, but allows you to tinker the properties of the first step separately from later steps. I suppose that neither of these is particularly more complex than the other. But it bothers me that nW and nR would be treated differently as to moving out of check is concerned.

The author, Gerd Degens, has updated this page.

Note that even a King and Commoner (nonroyal piece moving like a King) can checkmate a lone King on an 8x8 board, without using something like the King-Kaiser Faceoff rule. So a Kaiser and Duke can easily checkmate a lone King. Also the Checkmating Applet tells me that a Kaiser and two Eagles can checkmate a lone King in twenty moves or less. Dividing the Fairy Stockfish endgame values listed in the game by 2.76 yields:

Pawn=77, Knight=309, Bishop=332, Rook=500, Queen=972.

Soldier=98, Eagle=389, Cardinal=515, Tower=536, Duke=417.

I would guess that the minimum values are: Eagle=450, Cardinal=500, Tower=650, Duke=550. At least, I am reasonably certain that an Eagle and a Duke are a match for a pair of Cardinals. A final note: in a game of Empire Chess gaining Pawns seems more important than hanging on to all those higher valued pieces. My immediate goals would include trading an Eagle for Knight+Pawn and trading a Cardinal for Bishop+Pawn.

After fifteen years I finally decided on an excellent rating. One contributing factor was the Checkmating Applet telling me that a King and two (improved) Knights can checkmate a lone King in 33 moves or less on the 10x10 board.

Estimating Pawn=1, Knight=4, Bishop=4.5, Minister=5.5, Rook=6, Queen=10 points. I started with my usual values on the 10x10 board, then added 0.5 to the Rook and 1.0 to the Knight (8 more moves) and Bishop (4 more moves, plus no longer colorbound). Now a Queen is only worth as much as a Rook and a Knight.

The author, David Paulowich, has updated this page.

Indeed the Ajax Knight is 'potent', as the F move allows it to switch its attack from c1 to a1 in a single move (e.g. Nd3-c2). So it should be able to checkmate in combination with almost any piece.

Note that on 8x8 I never saw much effect of adding moves to a Bishop that lifted the color binding. Giving the Bishops of one player a single orthogonal non-capture step, and the other player that same move on the Knights, did not really swing the score away from 50%. If color binding is a handicap, it seems to manifest itself only for the unpaired piece, making its value less than half of that of the pair. This argues for the Knight gaining more from getting 8 moves than the Bishops gain from 4.

I also did some tests with multiple color-bound pairs (for evaluating the Color-Bound Clobberers CwDA army). The results were best explained by the theory that the intrinsic value of the pieces is half the pair value, but that you have to subtract a fixed penalty if the color bounds are not equally distributed over the two shades.

For the few divergent pieces I once tested the rule of thumb that their total value is the weighted average of the non-capturing and capturing components, where the later count twice as much as the former. So mQcN was around 5 (N=3, Q=9 scale), mNcQ around 7. The Tower and Cardinal can also be written as mQcR and mQcB, so I would expect values 6.3 and 5 for those.

Finalized version of Raichu Shogi.

Only differences from normal Chu Shogi are that the Lion-trading Rules are replaced by the shock rule (except King and Prince do not trigger it) and that Pawns and Lances must promote on the last rank due to not having any special abilities deriving from the shock rule.

When I try to open this game it shows an error saying

ILLEGAL: P f3-f5 on turn 1:

There was no P on f3. It is an empty space.

The game has no rule enforcement at all so it seems like it should work

I'm still curious about the origin of this game.

The only PDP-8 software called Kriegspiel is "a variation of chess, and is played by the same rules, except that neither opponent can see the other's position. They play on separate boards and there is a judge who tells them if their moves are legal and gives other information regarding the game."

So, Kriegspiel. Which leads me to believe the game went by a different title.

Internet Archive Link

This looks fun. Game courier?

Archaic Warfare by yoshilikes24-chesscraft94, AKA YoshiLikes

But with shuffle.

This one enforce rules.

Well, this one might already have been published, but the Diagram in it is awful: the board background image is not properly aligned with the pieces, and furthermore already has (oriental style) pieces on it.

It could be that I just uncovered this, as I finally managed to fix the use of background images in the Interactive Diagram. It appears that someone had installed a style file that globally broke all Diagrams on the site by defining a background color in table row (<tr>) elements. Which covered the background image the Diagram used for the <table>. I now discovered that explicitly specifying the <tr> background color as 'inherit' is a way to counter-act that. So all background images are now visible again.

Chess Battler Advanced