Fairy chess piece

Some fairy pieces

	Archbishop (knight + bishop compound)
	Chancellor (knight + rook compound)
	Grasshopper (shown as an upside-down queen)
	Nightrider (Knightmare) or unicorn (shown as an upside-down knight)

A fairy chess piece or unorthodox chess piece is a piece analogous to a chess piece. It is not used in conventional chess, but is used in certain chess variants and some chess problems. These pieces vary in the way they move and possibly in additional properties.

Because of the distributed and uncoordinated nature of unorthodox chess development, often the same piece is referred to by different names or the same name is used for different pieces in various contexts (chess problems, various chess variants).

Classification

Most (but not all) usual fairy chess pieces fall into one of three classes, although it should be noted that some are hybrid pieces (see the Chinese pieces, for example, which can move without capture as riders yet can only capture as hoppers). It is easy to create a new type of piece by simply combining the movement powers of two or more different pieces. Obviously the number of possible such pieces and the properties they may have are limited only by human imagination.

A specialized solving program, WinChloe, recognizes more than 1200 different fairy pieces.

Movement type

Leapers

An (m,n)-leaper is a piece that moves by a fixed type of vector between its start square and its arrival square. One of the coordinates of the vector 'start square - arrival square' must have an absolute value equal to m and the other one an absolute value equal to n. A leaper moves in the same way whether or not it captures, the taken unit being on the arrival square. For instance, the knight is the (1,2)-leaper.

The leaper's move cannot be blocked; it "leaps" over any intervening pieces, like the knight in standard chess.

In shatranj, a forerunner to chess, the pieces later replaced by the bishop and queen were also leapers: the alfil was a (2,2)-leaper (moving exactly two squares diagonally in any direction), and the fers a (1,1)-leaper (moving exactly one square diagonally in any direction).

Some pieces can be described as combined leapers, i.e. as pieces having the movement capabilities of multiple leapers. The king in orthodox chess (ignoring check restrictions) is an example of a combination of a (1,1)-leaper and a (1,0)-leaper.

Leapers are not able to create pins, although they are often effective forking pieces. One additional property is that the check of a leaper cannot be parried by interposing.

All orthodox chessmen except the pawn are either leapers or riders, although the Rook does 'hop' when it castles.

The Wazir is a (1,0)-leaper (an "orthogonal" one-square leaper); the Fers is a (1,1)-leaper (a "diagonal" one-square leaper). Both are used in Muslim versions of chess. The King of standard chess combines the two.

The Dabbaba is a (2,0)-leaper; the Alfil is a (2,2)-leaper; the Knight is a (1,2)-leaper. The Alibaba combines the Dabbaba and Alfil; while the Squirrel can move to any square 2 units away.

The 'level-3' leapers are the Threeleaper, a (3,0)-leaper; the Tripper, a (3,3)-leaper; the Camel, a (1,3)-leaper; and the Zebra, a (2,3)-leaper.

The Arabic word dabbāba formerly meant a type of medieval siege engine, and nowadays means "army tank".

	0	1	2	3
0	Zero	Wazir	Dabbaba	Threeleaper
1	Wazir	Fers	Knight	Camel
2	Dabbaba	Knight	Alfil	Zebra
3	Threeleaper	Camel	Zebra	Tripper

An amphibian is a combined leaper with a larger range on the board than its components. The simplest amphibian is the Frog, a (1,1)-(0,3)-leaper.

Riders

A rider is a piece that can move an unlimited distance in one direction, provided there are no pieces in the way.

There are three riders in orthodox chess: the rook can move an unlimited number of (1,0) cells and is therefore a (1,0)-rider; the bishop is a (1,1)-rider; and the queen is a (1,1)- or (1,0)-rider.

One of the most popular fairy chess riders is the nightrider, which can make an unlimited number of knight moves (that is, (2,1) cells) in any direction (though, like other riders, it cannot change direction half-way through its move).

Sliders are a noteworthy special case of riders which can only move between geometrically contiguous cells. All of the riders in orthodox chess are examples of sliders.

The names of riders are often obtained by taking the name of a leaper which moves a similar cell-size and adding the suffix "rider". For example, the zebra is a (3,2)-leaper, and the zebrarider is a (3,2)-rider.

Riders can create both pins and skewers.

Hoppers

A hopper is a piece which moves by jumping over another piece (called a hurdle). The hurdle can usually be any piece of any color. Unless it can jump over a piece, a hopper cannot move. Note that hoppers generally capture by taking the piece on the destination square, not by taking the hurdle (as is the case in checkers). The exceptions are called locusts.

There are no hoppers in orthodox chess, although in xiangqi, the cannon captures as a hopper (when not capturing, it is a rider which can not capture - the so-called "Chinese pieces" (see below) share this characteristic).

The most popular hopper in fairy chess is the grasshopper, which moves along the same lines as an orthodox queen, except that it must hop over some other piece and land on the square immediately beyond it.

Locusts

A locust is any piece which captures by hopping over its victim (as in checkers). It is sometimes considered a type of hopper.

Marine Piece

A marine piece is a combination piece consisting of a rider (for ordinary moves) and a locust (for captures) in the same directions. Marine pieces have names alluding to the sea and its myths, e.g., nereïde (marine bishop), triton (marine rook), mermaid (marine queen), or poseidon (marine king).

By game

Some classes of pieces come from a certain game; often these have a common set of characteristics.

Chinese pieces

Main article: Xiangqi

Chinese pieces are pieces derived from those found in xiangqi, the Chinese form of chess. The most common Chinese pieces are the leo, pao and vao (each of which are derived from the Chinese cannon) and the mao (derived from the horse). Those derived from the cannon are distinguished by moving as a leaper when capturing, but otherwise moving as a rider. Less frequently encountered Chinese pieces include the moa, nao and rao.

By special attributes

Royal pieces

A royal piece is one which must not be allowed to be captured. If a royal piece is threatened with capture and cannot avoid capture next move, then the game is lost (this is "checkmate"). In orthodox chess, each side has one royal piece, the king. In fairy chess any other orthodox piece or fairy piece may instead be designated royal, there may be more than one royal piece, or there may be no royal pieces at all (in which case the aim of the game must be something other than to deliver checkmate, such as capturing all of the opponent's pieces).

Xed pieces

Name	Notes
Crowned pieces	Any piece which, in addition to its normal powers, can move like a King.
Knighted piece	Any piece which, in addition to its normal powers, can move like a knight. For example, an amazon is a knighted queen.

Notations

Parlett's movement notation

In his book The Oxford History of Board Games David Parlett used a notation to describe fairy piece movements. The move is specified by an expression of the form m={expression}, where m stands for "move", and the expression is composed from the following elements:

• Distance (numbers, n)
  • 1 - a distance of one (i.e. to adjacent square)
  • 2 - a distance of two
  • n - any distance in the given direction
• Direction (punctuation, X)
  • * - orthogonally or diagonally (all eight possible directions)
  • + - orthogonally (four possible directions)
  • > - orthogonally forwards
  • < - orthogonally backwards
  • <> - orthogonally forwards and backwards
  • = - orthogonally sideways (used here instead of Parlett's divide symbol.)
  • >= - orthogonally forwards or sideways
  • <= - orthogonally backwards or sideways
  • X - diagonally (four possible directions)
  • X> - diagonally forwards
  • X< - diagonally backwards
• Grouping
  • / - two orthogonal moves separated by a slash denote a hippogonal move (i.e. jumping like knights)
  • & - repeated movement in the same direction, such as for hippogonal riders (i.e. the nightrider)

Additions to Parlett's

The following can be added to Parlett's to make it more complete:

• Conditions under which the move may occur (lowercase alphanumeric, except n)
  • (default) - May occur at any point in the game
  • i - May only be made on the initial move (e.g. pawn's 2 moves forward)
  • c - May only be made on a capture (e.g. pawn's diagonal capture)
  • o - May not be used for a capture (e.g. pawn's forward move)
• Move type
  • (default) - Captures by landing on the piece; blocked by intermediate pieces
  • ~ - Leaper (leaps)
  • ^ - Locust (captures by leaping; implies leaper)
• Grouping (punctuation)
  • / - two orthogonal moves separated by a slash denote a hippogonal move (i.e. jumping like knights); this is in Parlett's, but is repeated here for completeness
  • , (comma) - separates move options; only one of the comma-delimited options may be chosen per move
  • () - grouping operator; see nightrider
  • - - range operator

The format (not including grouping) is: <conditions> <move type> <distance> <direction> <other>

On this basis, the traditional chess moves are:

• King: 1*
• Queen: n*
• Bishop: nX
• Rook: n+
• Pawn: o1>, c1X>, oi2>
• Knight: ~1/2

Ralph Betza's "funny notation"

Ralph Betza created a classification scheme for fairy chess pieces (including standard chess pieces) in terms of the moves of basic pieces with modifiers.

Capital letters stand for basic pieces and components, besides the standard abbreviation for the chess pieces (R, N, B, Q, and K) the following letters are used: Wazir, Ferz, Alfil, Dabbaba, H (0,3)-leaper, Long Leaper (CameL), J (2,3)-leaper (Giraffe), and G (3,3)-leaper. Riders are denoted by duplication of the letter, e.g., NN is the funny notation for the nightrider piece; restricted range is denoted by a digit after the letter, e.g., R4 is a rook restricted to at most 4 steps.

Small letters in front of the capital letters denote modifications of the component. Often used modifiers are: forward, backward, right, left, sideward, vertical, move only, capture only, z crooked (moving in a zigzag line like the Boyscout), grasshopper, jumping (i.e., it must jump, cannot move without a hurdle), non-jumping like the Chinese Elefant, o cylindrical, pao (like the Chinese Cannon captures), and q circular movement (like the Rose).

In addition, Betza has also suggested adding brackets to her notation: q[WF]q[FW] would be a crooked king, which can move from e4 to f5 then g5, h4, h3, g2, f2, e3, and back to e4, effectively passing a turn.

Example: The standard chess pawn can be described in Ralph Betza's funny notation as mfWcfF (ignoring the initial double move).

There is no standard order of the components and modifiers. In fact, Betza often plays with the order to create somehow pronouncable piece names and artistic word play.

Addition to Betza's

Betza does not use the small letter i. It is used here for initial in the description of the different types of pawns.

Notable examples

Name	Parlett	Betza	Found in	Notes
Alfil	~2X	A	Shatranj	A (2,2)-leaper. Compare to Elephant. Alternate notation: ~2/2
Alibaba	~2*	AD	Fairy Chess Problems	Combines the powers of Alfil and Dabbaba
Amazon	n*, ~1/2	QN	Knightmare Chess	Combines the powers of the Queen and the Knight. Also called Superqueen.
Andernach grasshopper			Andernach chess	A Grasshopper that changes the colour of the hurdle it leaps over. Also known as a Chopper.
Archbishop	nX, ~1/2	BN	Capablanca chess	Combines the powers of Bishop and Knight. Also called a Princess, Cardinal, Janus or Paladin.
Balloon			Four Dimensional Chess	A Bishop-like piece used in four-dimensional chess, i.e. it changes all coordinates simultaneously while moving.
Basilisk	on* (Immo~1/2)	mQ (Immo-N)	Nova Chess	A piece that moves as a Queen but immobilizes any piece within a knight's move of itself, that is, it prevents it from moving or taking. If it is a fairy piece with additional powers it may or may not perform these other tasks depending on the case in question. A Basilisk that is caught by another Basilisk in this fashion, for example, may continue to immobilize others, including the other Basilisk.
Berolina pawn	o1X>, c1>, io2X>	mfFcfWimfF2	Berolina chess	Moves one square diagonally forward (except on its first move, when it may move two), but captures by moving one square straight forward. Compare with Pawn.
Bishop	nX	B	Orthodox Chess	Moves any number of free squares diagonally.
Boyscout		zB	Fairy Chess Problems	Moves like a bishop, but takes 90 degree turns after each step. Invented by J. de A. Almay in the first half of the 20th century. Rediscovered as Crooked Bishop by Ralph Betza.
Bug-Eyed Monster			Fairy Chess Problems	Can jump to any square which would not be reachable by any orthodox chess piece. Since the Amazon is the sum of all orthodox chess pieces, the Bug-Eyed Monster is the complement of the Amazon.
Camel	~1/3	L	Tamerlane Chess	Old historic piece. Jumps 2 squares orthogonally followed by one square diagonally outwards.
Cannon				See "Pao" and "Korean Cannon"
Cardinal				See "Archbishop"
Champion	1+, ~2*	WAD	Omega Chess	Combines the powers of the Wazir and the Alibaba.
Chancellor	n+, ~1/2	RN	Capablanca chess	Combines the powers of the Rook and Knight. Also called Empress or Marshal.
Checker	cn(^2X>), o1X> King: cn(^2X), o1X		Checkers	Multiple captures in one turn, or without capturing can move forward one diagonal space, but cannot move backward until after it has finished a turn on the far rank of the board. (cf. Draughts, Checkers)
Chopper				See "Andernach grasshopper"
Colonel	n>, n=, 2/1> 1*	KfsRfN	Chess with different armies	Moves as forwards and sideways Rook, the forwards moves of a Knight, or a King.
Dabbaba	~2+	D	Tamerlane Chess	Old historic piece, also known as War machine or Machine. Alternate notation: ~0/2
Dayrider	n(~2*)	AADD		Combination of Alfilrider and Dabbabarider. Also known as Alibabarider.
Dummy				A piece with no moves at all. It may be captured, gain temporarily moving ability by relay, or pushed or pulled around by other pieces if there are pushing or pulling pieces on the board. Different from Zero.
Edgehog	n*	Q	Edgehog Chess	A Queen that can move only to or from the edge of the board. Variant: when it moves from an edge, it may not move to an edge. Represented in diagrams by a Queen rotated 90° counterclockwise. Invented by John Driver in 1966.
Elephant	2X	nA	Xiangqi (Chinese)	A (2,2) leaper, but it cannot jump over an intervening piece, like the Ma. In Chinese Chess, the Elephant is restricted to its half of the board.
Empress				See "Chancellor"
Fers	1X	F	Shatranj	Move one square in any direction diagonally.
Fusilier	o1+, c1X	mWcF	Centennial Chess	Moves and captures like a Pawn in all 4 directions. Invented by F. Marinelli in 1770. Also known as Steward or Quadrapawn.
Giraffe	~1/4			Old historic piece. Jumps one square diagonally followed by three squares orthogonally. See also Zurafa.
Gold General	1+, 1X>	WfF	Shōgi	Moves in all 4 orthogonal directions or diagonally forward.
Grasshopper		gQ	Fairy Chess Problems	A hopper which moves along the same lines as a queen and lands on the square immediately beyond that of the hurdle. One of the most popular fairy pieces. In diagrams, the Grasshopper is usually represented by an inverted Queen.
Graz Pawn	1*> , io2*>	fWfFifmW2ifmF2	Fairy Chess Problems	Combines the powers of the Berolina Pawn and the standard Pawn. Also known as the Sergeant, this piece was used as early as 1943 in Arno von Wilpert's Wolf Chess. It occurs (without the initial double move) as Iron General in large Shogi variants from 15th century, e.g., in Tenjiku shogi.
Immobilizer	on* (Immo1*)	mQ (Immo-K)	Ultima	The Immobilizer, invented by Robert Abbott, moves as a chess Queen. At the end of its move, any enemy piece that is on a square adjacent to the Immobilizer is frozen in place, and can not move away until the Immobilizer moves away or is captured. The Immobilizer can never move to an occupied square and can not capture pieces. If two Immobilizers move next to each other, they are both frozen until the end of the game or until one is captured. An immobilised piece may commit suicide, e.g., to open a line of attack. This action counts as a move.
Janus			Janus chess	See "Archbishop"
King	1*	K	Orthodox Chess	Move one square in any direction. Royal in orthodox chess. A non-royal piece which moves in this way is sometimes called a Commoner or Man.
Khohn	1X, 1>	FfW	Makruk	Move one square in any direction diagonally or one square straight forward. It has the same moves as the Silver General in Shogi.
Knight	~1/2	N	Orthodox Chess	It jumps one square orthogonally followed by another square diagonally.
Korean Cannon		pR	Korean Chess (Janggi)	Moves and captures along orthogonal lines by jumping exactly one piece, called the hurdle. There can be any number of free squares before and after the hurdle. Unlike the Pao it moves the same way for capturing and non-capturing moves. In chess problems it is sometimes called Rook Lion or Rion.
Kraken	~n/m			Leap to any square on the board, including the one it is currently on (leaping to the current square has the effect of passing a move). Compare with Universal leaper.
Leeloo			Quintessential Chess	Combines the powers of Quintessence and Rook
Leo	on*, c^&	mQcpQ	Chinese	Combines the powers of the Pao and Vao; it moves like a Queen when not capturing (that is, a (1,0) or (1,1) rider), but captures by leaping over an intervening piece and taking the piece on the Leo's destination square (the captured piece can be any number of squares beyond the hurdle).
Lias' Pawn	o1>, o1=, c1X>, io2>	mfsWcfFimfW2	Lias' proposal	An extended Pawn which can also step one square sidewards. Proposed in the 1920s by A. G. Lias to improve standard chess
Lion		pQ	Fairy Chess Problems	A hopper which moves along the same lines as a Queen and which can land on a square any distance beyond the hurdle.
Maharaja	n*, ~1/2	QN	Maharajah and the Sepoys	A royal Amazon, the only piece for white.
Mao			Chinese	Moves like a Knight except that it does not leap. It first moves one square orthogonally in any direction, and then continues in the same general direction one square diagonally. The square it is on after its orthogonal move must be vacant. For example, if a white mao is on b2 and there is a white pawn on b3, the Mao cannot move to a4 or c4; if the pawn is on c3, however, it can move to both those squares (because the first part of the move is orthogonal, not diagonal).
Marshal				See "Chancellor"
Moa			Chinese	as the Mao, but the first step is diagonal and the second orthogonal, not the other way round.
Murray Lion	~2*, c1*	ADcK		Can move and capture as an Alfil or Dabbaba, and capture only as a King. This piece stems from a misinterpretation of the Lion of Chu Shogi but has become popular in fairy chess problems and chess variants. It is named after the chess historian Harold James Ruthven Murray who brought it up.
Nao		mNNcpNN	Chinese	A Chinese Nightrider —moves as a normal Nightrider (that is, a (2,1) rider) when not capturing, but which captures by leaping over an intervening piece and taking the piece on the Nao's destination square (the captured piece can be any number of knight-moves beyond the hurdle).
Nightrider	n(1/2) (in same direction)	NN	Fairy Chess Problems	A rider which moves any number of 2,1 cells (i.e., knight moves) in the same direction. A Nightrider on b2 on an empty board, therefore, can move to a4, c4, d6, e8, d3, f4, h5 and d1. A Pawn of the opposing colour on d6 could be captured, but the Nightrider could not move any further in that direction (i.e., it couldn't move on to e8). A pawn on b3, for example, would have no effect. On diagrams, the nightrider is usually represented by an inverted Knight. One of the most popular fairy pieces. See diagram below.
Odysseus			Fairy Chess Problems	The Odysseus' move depends on the file where it is located: It moves as a Rook on files a and h, as a Knight on files b and g, as a Bishop on files c and f, as a Queen on file d and as a King on file e. Also known as Querquisite.
Pao		mRcpR	Chinese	Moves like a Rook when not capturing (that is, a (1,0) rider), but captures by leaping over an intervening piece and taking the piece on the Pao's destination square (the captured piece can be any number of squares beyond the hurdle). Found in xiangqi (in which context it is normally known in English as a Cannon). Compare with Korean Cannon.
Pawn	o1>, c1X>, io2>	mfWcfFimfW2	Orthodox Chess	Moves one square straight forward (except on its first move, when it may move two squares), but captures one square forward diagonally. Compare with Berolina pawn.
Pentere			Quinquereme Chess	Combines the powers of Queen and Quintessence.
Princess				See "Archbishop"
Pterodactyl	~3/3, ~5/5, ~0/15		Chess mathematics	The simplest triple range amphibian. George Jelliss demonstrated a pterodactyl's knight's tour on a 16×16 board in 1985
Quang trung rook			Quang Trung Chess	Moves as Rook but when capturing must move on square away from captured piece in the same direction.
Queen	n*	Q	Orthodox Chess	Combines the powers of the Bishop and Rook.
Quintessence			Quintessential Chess	A Nightrider who takes 90-degree turns in a zig-zag manner on each step. First described in 2002 by Jörg Knappen and found in several chess variants since then.
Rao		mqNcpqN	Chinese	A Chinese Rose —moves as a normal Rose when not capturing, but captures by leaping over an intervening piece and taking the piece on the Rao's destination square. The captured piece can be any distance beyond the hurdle.
RennCavalier			Renniassance Chess	Moves in the same move one square diagonally and any number of squares othogonally or any number of squares orthogonally and one diagonally. It has two paths to the same target square and must make at least a blockable knight's move. Called Cavalier in RennChess, but the name Cavalier is used for other pieces as well. Renniassance Chess was invented by 1980 by Eric V. Greenwood.
RennDuke			Renniassance Chess	Moves in the same move one square orthogonally and then any number of squares diagonally or any number of squares diagonally and then one straight. It has two paths to the same target square and must make at least a blockable knight's move. Called Duke in RennChess, but the name Duke is used for other pieces as well.
Rook	n+	R	Orthodox Chess	Moves any number of free squares orthogonally.
Rose		qN	Fairy Chess Problems	Moves as a Nightrider, except that rather than moving in a straight line, it moves along pseudo-circular ones. A rose standing on e1 on an empty board, for instance, can move to any of the squares on the large circle c2, b4, c6, e7, g6, h4 and g2; as well as c2 and a1; or d3 and b4; or d3, e5 and g6; or f3, e5, c6 and a5; or f3 and h4. As with the nightrider, an opposite-coloured piece on any one of these squares can be captured, but prevents the rose from progressing any further along that line. See diagram below.
Spy	2>, 2=, (1/1)>	fsDfF	Chess Empire	The Spy can move two spaces forwards or sideways, or can move like a knight one forward and then one horizontally or vice versa. It can leap over pieces and can only move two spaces; thus, it is "trapped" on its own color like a Bishop.
Squirrel	~0/2, ~1/2, ~2/2	DAN	Fairy Chess Problems	Jumps to any field in a distance of 2. It was discovered independently several times and is also known as Centurion or Castle.
Superpawn	on>, cnX>	mfRcfB	Fairy Chess Problems	Moves without capture any number of fields forward, captures diagonally forwards like a Bishop. Promotes on the 8th rank. Cannot capture en passant nor be captured en passant. May be placed in the first rank. Invented by Werner Speckmann in 1967.
Superqueen				See "Amazon"
Taxi			Fairy Chess Problems	Moves without capture one step forward or backwards, captures one square diagonally forwards like a Pawn. When in the second rank can move one, two or three steps forward or one backwards. Can promote on the 8th rank or continue to be a Taxi. Can capture en passant other Pawns or Taxis. May be placed in the first or eight ranks.
Universal leaper				Leap to any square on the board apart from the one it is on. Compare with Kraken.
Unicorn			Raumschach	In Raumschach it is a triagonal rider, moves through the vertices of the cubes. See diagram below. The name Unicorn is also used for several pieces in 2 dimensions, e.g., for the Archbishop or for the combination of Bishop and Nightrider also known as Banshee.
Vao		mBcpB	Chinese	Moves like a Bishop when not capturing (that is, a (1,1) rider), but captures by leaping over an intervening piece and taking the piece on the Vao's destination square (the captured piece can be any number of squares beyond the hurdle).
Wazir	1+	W	Tamerlane Chess	Moves one square orthogonally in any direction.
Wizard	1X, ~1/3	FL	Omega Chess	Combines the movement of Fers and Camel.
Zebra	~2/3	J		Old historic piece. Jumps one square orthogonally followed by two squares diagonally outwards.
Zero	~0/0			A piece which can make a zero move, i. e., jump and land on its starting square without any side effects. This gives the player the option to pass a move. Sometimes used as a component to more complex pieces. It is different from the piece with no move at all called Dummy
Zurafa			Tamerlane Chess	Starts with a (1,4) leap (like the modern Giraffe) and may continue moving outwards as a Rook.

a b c d e f g h 8 8 7 7 6 6 5 5 4 4 3 3 2 2 1 1 a b c d e f g h Nightrider makes any number of knight moves in the same direction.

a b c d e f g h i j 10 10 9 9 8 8 7 7 6 6 5 5 4 4 3 3 2 2 1 1 a b c d e f g h i j Rose. Moves as Nightrider, but along pseudo-circular lines. (two possible paths depicted.) Of course it may move clockwise or counter-clockwise.

E	D	C
B	A
The unicorn, represented here by an up-side-down knight, moves through the vertices of cubes, triagonally. A unicorn from its starting position can only reach 30 cubes. The white unicorn's destination squares are marked with a circle, black's with an X. It is important to remember that the boards are stacked, with board E on top.

References

• David Parlett (1999). The Oxford History of Board Games. Oxford: Oxford University Press. ISBN 0-19-212998-8.
• Christian Poisson. "Catégories de pièces - Types of pieces". Retrieved 2008-04-18.
• Christian Poisson. "Pièces – Pieces". Retrieved 2008-04-18.
• Ralph Betza's funny notation
• George Jelliss. "All the King's Men". Retrieved 2010-07-20.

External links

• Piececlopedia - an extensive list of fairy chess pieces, their history and movement diagrams
• Who is Who on Eight by Eight Compiled by Ivan A Derzhanski, shows also piece values
• Jerome Grimbert's List of Fairy Chess Pieces (french)
• Fairy chess pieces and fairy problem conditions (german)
• Märchenschachlexikon (Die Schwalbe, German)