Intro
I'll keep this article as a simple ("simple" with respect to multidimensional chess) rules guide, and not get into the reasons for how these came about. There is a Game Courier preset at
http://play.chessvariants.org/pbm/play.php?game%3DTessChess%26settings%3DTessChess
The Board
This is a four dimensional variant, played in a 4x4x4x4 hypercube (aka a tesseract, hence "Tess"Chess). We will visualize this hypercube via a 4x4 array of 4x4 chessboards. With this layout, it is natural to identify two of the directions as "forward/backward" and two as "left/right"; one of each is a "big" direction, and the other is "small". We label the squares in this array with four entries: a capital letter A-D signifying the big column, a lowercase letter a-d signifying the small column, and two numbers 1-4 signifying the big and small row, in that order.
Setup
Starting setup for white is:
Rooks at Ab11 and Dc11
Bishops at Ac11 and Db11
Knights at Bb11 and Cc11
Queen at Bc11
King at Cb11
Pawns at Ab22, Ac22, Bb22, Bc22, Cb22, Cc22, Db22, and Dc22.
Black starts as white's mirror image, lying entirely in rows 33 and 44.
Notice that this is almost similar to a standard chess setup. The reversed knight and bishop was intentional. This setup is subject to change during playtesting.
Piece Movement
All movements make full use of the four dimensions and the diagonals.
Pawns
Pawns move without capturing by moving one square in either of the "forward" directions. They capture by moving one square in either forward direction and one square in either lateral direction. There is no initial two-step. Pawns may promote upon reaching the forwardmost row (44 for white, 11 for black).
Be careful! Pawns have been known to launch surprise attacks! It is easy to underestimate pawns, but they now have a possible eight squares of attack.
Kings
A king may move one square in any direction, including any diagonal, triagonal, or quadragonal. (If you are unfamiliar with these terms, a diagonal step is one which changes two of a piece's coordinates by +1 or -1 independently, a triagonal step changes three, and a quadragonal step changes all four coordinates.) There is no castling.
A king's possible moves can be easily visualized as the collection of all 3x3 groups of squares centered at the king's position in each of the nine boards around the king.
Queens
Queens move kingwise, but may continue in the same direction as long as they are unobstructed.
It is sometimes helpful to think of a multi-agonal move as being composed of its individual orthogonal movements. For instance, a single triagonal step might be built up of movements big-forward, small-left, and small-backwards. These intermediate steps do not have any real effect on the game (any square occupied by one of these steps does not block the movement), but help one to make sure that a piece continuing in the "same direction" is really in the same direction. Here's a diagram of a rook making a triagonal movement, with intermediate steps shown:
Bishops
Bishops may move along any diagonal or quadragonal. Notice that this restricts them to one of two colors on the board.
Diagonal moves are green, quadragonal ones are blue. Squares are darker when they are further from the bishop.
Rooks
Rooks may move along any orthogonal or triagonal. It may take some getting used to seeing rooks move triagonally.
Orthogonal moves are green, triagonal ones are blue.
Knights
Knights move two squares in any direction and one square in a different direction (the two directions cannot be opposites of each other either). They are the only leapers in this game.
One of the main things I don't like about the original setup is that all bishops are stuck on dark squares. I know I've come up with another setup where this doesn't happen but the pieces still guard one another well, but I don't recall it now…it may be just swapping the positions of KN and BR on the right.
Might have been Gabriel Maura that came up with the idea of bishop castling, where K and B change places as a move. Maura's chess was 9 across, with 2 queens, so his bishops were both on the same color. He allowed them to stay that way, or castle with 1 B and K.
Hey Ben, could you use this setup, with the pawns pushed up?
That suffers the same problem; notice that the colors on your image don't switch from board to board. That setup, incidentally, is equivalent to
_RN_ _BQ_ _KB_ _NR_
which looks a lot like the standard layout. I believe I started with that setup, but didn't like that the rooks were guarded only by the royals.
Hey, Ben, that's Abdul-Rahman Sibahi's alternate setup for mine. He reverses the coordinates of my setup between big and little squares, so it is the same. Okay, how about this: expand the board to 4x4 x 6x6, where there are 16 levels - big squares - and 6x6 = 36 little squares in each one. This is a great increase in size, as you are adding 20 more little squares to each big square, which started with 16 little squares. You wind up with 576 little squares, from 256. But you still only have 16 levels, and here's the advantage - the change in dimensions the way I suggest prevents the pieces from bearing directly on each other from the starting setup. The diagonals now place the pieces in front of the pieces on the back level, instead of in them.
I found another idea I had for a setup:
oNRo KooB QooB oNRo
with a few extra pawns in the middle two big columns to cover the extra width.
This fixes the bishop coloring, and we have that the rooks guard the knights, the knights guard the bishops, and the bishops guard the rooks. Nice, but rather different.
Well, then, shall we push pieces? It's really the best way in cases like this. Send me an invite.
Hey, Ben, you can/should put a white pawn on B2c2 in the pawn movement-capture diagram.
Hey, Ben, in the intro, you dodge designer notes. I quote: "Intro
I'll keep this article as a simple ("simple" with respect to multidimensional chess) rules guide, and not get into the reasons for how these came about. There is a Game Courier preset at http://…"
Well, now that your game is working fairly well, you should do those Notes. You should give a brief design history [put in all the interesting spots], explain your thinking, and acknowledge your sources and inspirations, any collaborators, even your playtesters. How many people have heard of Vernon Rylands Parton?