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Turning Chess

The Rules of Turning Chess

The rules of Turning Chess are those of Chess, except for one simple rule: after a piece moves, it may be rotated one-eighth of a full turn.

Observations about Turning

Notice I said "may". Turning is optional, and you get to choose to turn left or turn right.

Turning happens after a move, therefore a piece may not turn without moving.

Some other games have an element of turning, but neither as free nor as generalized as in Turning Chess.

Pawns turn, too. For example 1. f2-f3 (turns right), 2. f3-g4 (right), 3. g4-h4 (no turn), and now the P at h4 is dead, can never move or capture. This is permitted, but you will very rarely want to do it.

If you use the FIDE army, only Pawns, Rooks, and Bishops are affected by turning. I believe it would be much more interesting to use any of the armies from Chess with Different Armies, or to use the Amontillado Army. (Most probably, the armies do not stay close enough in value to be used against each other; but feel free to try!).

The Fibnif, for example, produces four different movement patterns as it turns. In case my description of the idea of Turning has been insufficient, I illlustrate the idea of Turning by showing the four rotations of the Fibnif in this UAD[1].

 . . . . . . . .    . . . . . . . .    . . . . . . . .    . . . . . . . .
 . . . . . . . .    . . . . . . . .    . . . . . . . .    . . . . . . . .
 . . x . x . . .    . . x . . . . .    . . . . . . . .    . . . . x . . .
 . . x . x . . .    . x . x . . . .    . x x . x x . .    . . . x . x . .
 . . . O . . . .    . . x O x . . .    . . . O . . . .    . . x O x . . .
 . . x . x . . .    . . . x . x . .    . x x . x x . .    . x . x . . . .
 . . x . x . . .    . . . . x . . .    . . . . . . . .    . . x . . . . .
 . . . . . . . .    . . . . . . . .    . . . . . . . .    . . . . . . . .
The Bishight (fBbN) moves forward as a Bishop and backwards as a Knight. If it turns right four times, it becomes a Knishop (fNbB), which moves forward as a Knight and backward as a Bishop. There are eight different movement patterns for this piece, based on its current rotation.

When thinking about the position a few moves in the future, it is more useful to remember the current move pattern than to remember which way a piece is "facing".

This game was inspired by the Rose.

Values of Turning Pieces

A Turning Bishop is obviously worth as much as a Turning Rook; you can turn it into a Rook and keep it that way.

A Turning Rook is more valuable than a normal Rook, by some unknown amount; the reason is that, although it momentarily becomes a less valuable piece when it turns, you will turn it only when it is to your advantage to do so -- having the option to turn is better than not having it.

The same applies to all Turning pieces; they are more valuable than non-Turning pieces, by some unknown but reasonably small amount; but the added strength is likely to be important. This is unfortunate. If a Turning Half-Rook were worth half a Rook, it would be another nice way to make composite pieces. (Maybe a turning piece that *must turn* would work?)

Note: A Half-Rook would be a piece that moves forwards and backwards Rookwise, but not sideways. A normal half-Rook can never leave the file it starts on, but a Turning Half-Rook has the ability to visit the whole board. Also, a Turning Half-Rook has quite an interesting move, don't you think?

There is no such thing as a Turning Queen because all rotations are identical; it turns but stays the same. This is also true of King and Knight, and it means that they do not benefit from the value boost that true Turning pieces get.

About Turning Pawns

Pawns are very important to the game of Chess, and giving them the ability to turn makes a big difference in the game. Although a Turning Pawn can turn around and go back towards its own first rank, it takes several moves to do so, and then it suffers from being many moves away from possible promotion.

Imagine, for example, a White Pawn on a7 facing South. This is impossible, of course, but you can see that instead of being able to move to a8 and make a new Queen, this poor Pawn needs to go to a6 and turn, b5 and turn, c5 and turn, then d6 and perhaps turn, then the 7th rank and finally the 8th and promotion -- a total of 6 moves, compared to the maximum of 5 that a normal pawnd can need to go from its second rank to promotion.

In the endgame, an Turning Pawn is almost always a passed Pawn, unless it is immediately blocked; it can move and turn, and reach promotion while evading the opposition.

In the opening, the handling of Turning Pawns is tricky. For example, if 1. d2-d4 (turn right) e7-e5 (no turn) blocks the movement square and also attacks d4; but if 1 d2-d4 (no turn, then d7-d5 (turn left) both blocks the W Pawn's movement and also attacks it.

Turning QuarterHorses

The lance from Shogi moves like a Rook, but only straight forwards; as such, it's not a wonderful piece to use in most games.

A Turning Lance, which starts the game moving as a forwards Rook, but which has the option of turning on each move it makes, would be an interesting piece in many games. If you had a Turning Lance on h1, you might develop it by playing h2-h3 followed by tfRh1-h2(r), attacking the central square e5; then later if the attack on e5 became unprofitable you could continue tfRh2-g3(r or l), turning towards g7 or a3, depending on where you'd feel there was more profit to be found.

The Shogi Knight moves like a Knight, but to only the two most forward squares; that is, to one-quarter of the squares a Knight can move to. There are four other possible choices of two squares after you allow for rotations, and these pieces may be called Quarterhorses. A normal piece which moves differently to the right and to the left seems very strange, but a turning piece which is different r and l is acceptable; and so if you had a Quarterhorse that could move from f3 either to e5 or d2, and you started this piece on g1, it would seem logical to have the symmetrical piece (able to move from c3 to either e2 or d5) start the game for you on b1.

There are also four types of Quarter Queen, which would have one Rook direction and one Bishop direction.

That's a whole army, and so we have

Turning QuarterHorse Chess

The rules are those of Turning Chess, but the armies (potentially the players have different armies) are chosen from the list of quarter pieces given above. An additional rule is that a player may either have two identical Quarterhorses or two symmetrical Quarterhorses, and in addition must choose the initial orientation of all the pieces. (The Pawns must start by moving straight forward.)

Normal Kings and normal Turning Pawns are used. (Is there such a thing as "normal Turning Pawns"?)

The armies are weaker than the Shatranj army, so bare king should be a win; however, the unique nature of the pieces guarantees that the game will be interesting to play.


I once jokingly spoke of Octolings, but what would a Turning Halfling Quarter-Rook be if not an .... Octoling! The rules of Turning Octoling Chess are easily derived from the above. Turning Octoling Chess will never be played. Nobody will ever try even one game; or if somebody does try it, they will become famous and, after they are released from the mental institution, they will go on all the TV talk shows to describe the experience of playing Turning Octoling Chess.


[1] UAD == Ugly Ascii Diagram


When sending this text to Hans Bodlaender for inclusion on this website, Ralph wrote:
Well, Halflings was just one idea, even though I did wind up writing a lot about it. While I was doing so, I got another idea or two. I hope I won't have to write as much about them. I hope, in fact, that this is both the beginning and the end of the story of Turning Chess.
But ... well, read more on Turning and Churning...
Written by Ralph Betza. Postscript added by Hans Bodlaender.
WWW page created: April 10, 2001. Last modified: April 11, 2001.