OOC - diamond chess

[sythyry]

Sythyry doesn't talk about this much -- zie barely plays -- but many students (and others) enjoy it. These are draft rules for the game of diamond chess, which have been bopping around in my head for a few years. I haven't playtested it at all. If you do, please let know how it goes.

Diamond chess is played on an 8-by-8 board by two players. The players get two opposite corners. The diagonal separating them is called the "river". The pairs of diagonally-adjacent squares crossing the river are the "fords".   The actual board is rotated 45 degrees,  to be a diamond shape, but I can't do that in HTML.

Here are the fords marked with f's:

						f
					f		f
				f		f
			f		f
		f		f
	f		f
f		f
	f

Object: to capture your enemy's town piece.

Pieces: There are eleven pieces: one of each kind, except for three cani. The kinds are named after the World Tree species, plus "town". Pieces move in vaguely chesslike ways. They cannot move through each other or occupy the same square, except as noted.

Setup: The players start with their towns in the opposing corners (t). They take turns putting one piece down, following the numbers below. This should be done very fast -- without pauses to think.  If you put a piece down in the wrong order but a legitimate cell and you were going to move first, you now move second.

t	2	9	10
4	3	8
5	6	7
11
							10
					7	8	9
					6	3	4
				11	5	2	t

Order of Play: The game is a sequence of turns, ordinarily with the players alternating turns. A player may either move two pieces, or attack with one piece. (Moving a pack of cani counts as a single move, even though two or three pieces are moved. A sleeth's pounce counts as an attack, even though a piece is moved as well.  A khtsoyis' three attacks count as one attack move.) 
A very typical sequence is: Player one moves two pieces where they threaten enemy pieces, and are threatened once each in turn. Player two takes one of the two that got moved. Player one takes with the other one. 

Customs: Gameplay is fast. It is impolite to think more than 15-30 seconds (unless you are a novice and have to ask about the rules). If you wait more than a minute, your opponent can make a "small half-move" to spur you on -- that is, move one piece by one square (except that a Zi Ri would do an ordinary move 'cause it can't move just one square).   If you wait another minute past that, you forfeit that turn.

Winning: The game is won when one player captures the other one's town. This is capture, not checkmate as in Western chess. A strong player may choose a handicap of one or more checkmates -- she must checkmate the weaker player, then release him as soon as possible, that many times before she can capture his town and win.

Pieces can attack if they are adjacent to each other. There are three kinds of attacks: "weapon", "pounce" and "magical". Weapon attacks can be used on one of the four squares horizontally or vertically connected to the attacker ("w" in the picture below, with the attacker at 'a'). Magical ones can be used on one of the four squares diagonally connected to the attacker ("m" in the picture). Pounce combines moving and attacking: the attacker moves onto the defender and takes it in a single action (as in terrestrial chess).

m	w	m
w	a	w
m	w	m

Some pieces resist some attacks. Gormoror resist the first weapon attack on them, and Rassimel resist the first magical attack. (In actual sets, those pieces have markers for whether the first attack has happened or not.) The first attack of that kind won't capture the piece; the second one will. Herethroy resist all weapon attacks, and zi ri resist all magical attacks. There's no point to even trying. The sleeth's pounce cannot be resisted.

Piece	Movement	Capture	Defenses
town	One square in any direction. Must stay against the edge of the board. Cannot enter the river.	Cannot capture	No defenses. If it is taken, that side loses.
cani	There are three cani pieces. A cani not adjacent (horizontally or vertically) to another cani can move one square in any direction. A cani adjacent to one other cani can move two -- and both cani can move in the same turn. A cani adjacent to two other cani can move three -- and all three cani can move in the same turn. Cani can cross the river but cannot land in it.  They cannot use the fords (since they cannot move diagonally)-- they must cooperate to get across it.	weapon	No defenses
gormoror	Gormoror can move up to three squares horizontally or vertically. They cannot land in the river, but they can leap over it.	weapon	Resists one weapon attack.
khtsoyis	One square in any direction. Can land in the river. (Technically, this is called "floating over the river", but that doesn't matter for gameplay.)	weapon -- and can attack three times in the same turn	no defenses
herethroy	1-3 squares in any direction. Can cross the river (by hopping over, or moving through a ford) but not land in it.	weapon, but only on its own side of the river	Resists all weapon attacks
orren	1-3 squares horizontally or vertically. Can go in the river. If in the river, can go to any other river square (regardless of pieces in the way).	magic	Resists all weapon attacks if in the river.
rassimel	1-2 squares horizontally or vertically, but not through or into the river. Can go 1 square diagonally to cross the river at the fords.	magical or weapon.	resists the first magical attack.
sleeth	1-3 squares in all directions.  Can land in the river (technically "floating over the river").	pounce	no defenses
zi ri	Knight move (one square horizontally/vertically, then one diagonally). Can fly over other pieces.  Can land in the river (technically "flying over the river").   A zi ri can occupy the same square as another piece of either side.  However, if it is occupying an enemy piece's square and the enemy chooses to attack rather than move, the zi ri is taken in addition to whatever other effect the attack has.  (This is known as "a glorious sacrifice.")	magical	Resists all magical attacks

Solitary cani moves (cani is at 'c' and moving to '*')

	*
*	c	*
	*

Two cani moves (c1 moves to 1's; c2 moves to 2's.)  c1 can't move into the river, but c2 can hop over it.  Also c1 and c2 can go to the squares currently occupied by the other -- e.g, they could shift left by one or two cells.

			1	2
			1	2
	1	12	c1	c2		2
			1
				2

Three cani moves (c1 moves to 1's, c2 to 2's, c3 to 3's.  Also c1 can move to where c2 is, and so on.).  c1 is adjacent to c2; c2 is adjacent to c1 and c3; c3 is adjacent to c2.  (But c1 and c3 are not adjacent).  So, c1 and c3 can move 1-2 squares, but c3 can move 1-3.  Note that all three cani can cross the river, but they are separated when they get to the other side.

			2	1
			32	1
2	2	12	c2	c1		12
	3	3	c3		3
				1
			23

rassimel moves.  The lower rassimel's moves are marked by +. The upper one's are marked by * -- note that it has the special diagonal move to cross the river at the ford.

				*
				*
		*	*	r
					*+
					+
			+	+	r	+	+
					+
					+

Khtsoyis and zi ri moves

*	*	*
*	k	*
*	*	*
				+		+
			+				+
					z
			+				+
				+		+

Places that a town can go are highlighted.  town moves are indicated by +'s or *'s.

*	t	*			+	t
*
+
t
+

Comments

[sythyry.livejournal.com]

That wouldn't be diamond chess then. It might be a better game of course.

[kensaro.livejournal.com]

Ah yes, that was my other question, is the reason it's called diamond chess solely because of the shape of the board?

[sythyry.livejournal.com]

Yup!