A Game Courier Preset for Butterfly Chess

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Butterfly Chess

Uncoded. No rules enforced. No legal moves displayed.

Welcome to Game Courier, where you can play Butterfly Chess and many other Chess variants through online correspondence.

Rules of Butterfly Chess

In Butterfly Chess there are 7 piece types. Pawns, bishops, rooks and kings are used, as in chess, and there are 3 other piece types:

the Butterfly - moves as a knight, except it can move one space diagonally backwards instead of being able to make the knight's two rear-most moves, and it can move like a camel sideways in a forward direction instead of being able to make the knight's two sideways moves that are also forward. Ralph Betza alluded to such a piece type's way of moving in an article on his Mushroom piece type (Butterfly powers are diagrammed further below, too): Mushroom

the Flying Dragon - moves like a bishop or camel, and is also known as a caliph; Charles Gilman discusses this piece type in the following link (Flying Dragon powers are diagrammed further below, too): Caliph

the Advancer - The Advancer's method of movement and capture are different from each other: The Advancer moves as a chess Queen - that is, the Advancer can move any number of squares in any direction, orthogonally or diagonally, as long as all the squares it passes over are unoccupied by other pieces. The Advancer can never move to a square occupied by a piece of either side. To capture, the Advancer must move directly towards an opposing piece, and end its move on the square adjacent to that piece. Again, the Advancer can cross any number of unoccupied squares in any direction to make its capture. Note that if the Advancer moves directly towards a piece and lands adjacent to it, capturing that piece is not optional - the piece must be removed. Ben Good discusses this piece type: Advancer

Here's a diagram showing all the legal moves (i.e. leaps) that a Butterfly can make on an empty board - note that forward movements are not symmetrical with rear ones, and that the pattern as a whole looks like a butterfly (as Betza put it):

Here's a diagram showing all the legal moves that a Flying Dragon can make on an empty board - note that the flags show where it can move to when acting like a bishop, and the stones show where it can move to when leaping like a camel (notice also that it is a colour-bound piece):

Pawns can promote to any piece type in the setup, except for a king. They can initially advance 2 or 3 steps, rather than just 1 step, if unobstructed. Capturing en passant, is allowed, even if the pawn took a triple step. The capturing pawn would land on the square that is diagonally in front of it on the same file as the enemy pawn that just moved. Here's a link to Omega Chess, which has very similar rules governing legal pawn moves; note the examples of en passant captures: Omega Chess

Castling is allowed, with similar conditions as in chess, though in Butterfly Chess the king would move three squares to the left, or three squares to the right, as part of making such a move, and otherwise the rook involved would end up adjacent to the king, as in chess.

Stalemate, 50 move rule or 3-fold repetiton are draws, as in chess.

Here's a page about this game: Butterfly Chess

How to Move Pieces

Full Algebraic Notation

Algebraic notation identifies each space by a coordinate that begins with its file label and ends with its rank label. On the Chess board, files go up and down from one player to the other, and ranks go from left to right. In most games, files are represented by letters, and ranks are represented by numbers, but there is no fixed rule requiring this for all games, and some games, such as Shogi, reverse this convention. If you look at the diagram, you will usually see the file labels going from left to right and the file labels going up and down. And if you hover your mouse over a space, you will normally see the name of the coordinate appear in a tooltip.

It is not uncommon to see algebraic notation being used for Chess, but it is often in an abbreviated format that requires you to know both the rules of the game and the current position to know exactly which piece moves where. For example, the notation "Ne6" indicates that a Knight is moving to e6, but it doesn't indicate which Knight, and it doesn't specify where the Knight is coming from. To figure this out, you need to know how a Knight moves and which Knight on the board can make a legal move to e6.

Although rules may be programmed for individual games, Game Courier itself does not know the rules of any game, and it is unable to parse abbreviated algebraic notation. Therefore, it relies on full algebraic notation, which completely specifies the move without requiring any knowledge of the game's rules or the current position. The most usual type of full algebraic notation indicates the piece that is moving by its label, the space it is moving from, and the space it moving to. In Chess, a typical first move might be written as "P e2-e4". When you hover your mouse over a piece, you will normally see the piece label followed by the coordinate for the space, and when you hover it over an empty space, you will normally see the coordinate label. Including the piece label in your notation allows Game Courier to check that the piece you're moving is the right one, and it makes game notation easier to follow, but it is not mandatory.

You may promote a piece by including a promotion move after your regular move. A promotion move has a piece go directly to a coordinate. Here is an example: "p e7-e8; q-e8".

You may remove a piece from a space by adding an @ to the space or by omitting the destination coordinate. For example, both "@-e4" and "e4-" would remove the piece on "e4". This is useful for en passant when you are playing a game that does not handle this automatically. For example, "P d5-e6; e5-" removes the Pawn on e5 after a Pawn moves from d5 to e6.

You will not need to remove spaces for most games, but if you should need to, you can do this by omitting the first coordinate in a move. For example, "-e4" would remove e4 from the board. To add or return a space to the board, you may add an @ or any other piece to it.

Available Pieces

Pieces are represented by labels, usually using uppercase letters for White and lowercase letter for Black. When you enter a move or specify the starting position for a game, you should remember that piece labels are case-sensitive. Many piece sets are available for use with Game Courier, and this table shows you which pieces belong to the piece set you are currently using.

These pieces come from a set containing more pieces, but this preset has had the set of pieces reduced to those used in the game.

Credits

This preset uses the default settings file for Butterfly Chess, which was made by Kevin Pacey.

Game Courier was created, programmed and written by Fergus Duniho.

Game Courier, Copyright © Fergus Duniho, 2001-2017