wyrm/docs/source.md

The source text

Wyrm follows "Dragonchess" by Gary Gygax, Dragon Magazine No. 100 (volume X, number 3), August 1985, pages 34 to 40, published by TSR, Inc. The keeper owns the issue. This transcription was made from photographs of it with Apple's text recognition and then read against the pages by hand. The movement diagrams are described in words after each piece; where a diagram and the text disagree, or the text disagrees with itself, the section "Decisions" at the end says what the engine does.

Page breaks and the magazine's running heads are left out. The article's own headings are kept. Nothing has been reworded.

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DRAGONCHESS

by Gary Gygax

The DRAGONCHESS™ game is a fantasy-based variation of chess, in which the object of the game (as in standard chess) is to checkmate the opposing King. An understanding of the rules of chess is helpful in order to understand how DRAGONCHESS is played.

The playing surface for DRAGONCHESS is a three-tiered structure of rectangular boards, with each board composed of a grid 12 squares wide and 8 squares deep. The squares are alternately colored light and dark (or other color tones that contrast with each other), configured so that a light-colored square is in the near right-hand corner when the board is viewed from the longer side. The upper board represents the air, the middle board the land, and the lower board the subterranean world. To simulate the various environments, it is suggested that the squares on the upper board be colored light blue and white; on the middle board, light green and amber; and on the lower board, red and brown. Each board is the starting place for pieces particular to its environment; some pieces cannot move up or down off the board they begin on, but other pieces can travel between two or even all three boards. The opposing forces are designated as Gold and Scarlet, with Gold always moving first.

Setting up

At the start of the game, each player's pieces are positioned as shown in the accompanying diagram. Each force on the upper board consists of six Sylphs, two Griffons, and one Dragon. On the middle board, each side possesses one King, one Mage, one Paladin, one Cleric, two Heroes, two Unicorns, two Oliphants, and twelve Warriors. Each side's force on the lower board is made up of six Dwarves, two Basilisks, and one Elemental. In all, there are 42 pieces per side, or a total of 84 pieces in the game.

The diagram "Starting position, upper board", Scarlet at the top and Gold at the bottom, files a to l left to right:

8  . . G . . . Dr . . . G .
7  S . S . S . S . S . S .
6  . . . . . . . . . . . .
5  . . . . . . . . . . . .
4  . . . . . . . . . . . .
3  . . . . . . . . . . . .
2  S . S . S . S . S . S .
1  . . G . . . Dr . . . G .
   a b c d e f g  h i j k l

"Starting position, middle board":

8  O U H T C M K P T H U O
7  W W W W W W W W W W W W
6  . . . . . . . . . . . .
5  . . . . . . . . . . . .
4  . . . . . . . . . . . .
3  . . . . . . . . . . . .
2  W W W W W W W W W W W W
1  O U H T C M K P T H U O
   a b c d e f g h i j k l

"Starting position, lower board":

8  . . B . . . E . . . B .
7  . D . D . D . D . D . D
6  . . . . . . . . . . . .
5  . . . . . . . . . . . .
4  . . . . . . . . . . . .
3  . . . . . . . . . . . .
2  . D . D . D . D . D . D
1  . . B . . . E . . . B .
   a b c d e f g h i j k l

Notation and terminology

In the following descriptions of how pieces move and capture, squares on the board(s) are described in algebraic notation, with files (columns) labeled "a" through "l" reading left to right from Gold's viewpoint, and ranks (rows) numbered 1 (nearest to the Gold player) through 8 (nearest to the Scarlet player). A numerical prefix of 1 (upper board), 2 (middle board), or 3 (lower board) designates the board on which a certain square is located. Thus, "1a1" is the square in the near left-hand corner of the upper board, as viewed from the Gold player's position, and "3l8" is the square in the far right-hand corner of the lower board. Each piece is identified by the initial letter of its name ("S" for Sylph, etc.) except for the Dragon, which is identified by "Dr" to distinguish it from a Dwarf piece.

In all other respects, movement and capture notation is essentially the same as for standard chess. A full description of this notation is given near the end of this text.

Standard chess pieces are referred to frequently in the descriptions of how DRAGONCHESS pieces move and capture; in such cases, their names (king, rook, etc.) are not capitalized, while the names of DRAGONCHESS pieces are always capitalized. In the diagrams of movement that accompany the description of each piece, "M" designates a square that a piece can move into, if that square is unoccupied (i.e., no capture is permitted); "C" designates a square that can be occupied only if a capture is involved; and "X" designates a square that can be occupied either by a capturing or a non-capturing move.

Because many pieces can move in three dimensions, nomenclature for movement between squares has been standardized as follows: "horizontal" refers to a side-to-side move as viewed by the player moving the piece; "vertical" is a move forward (toward the opponent's side of the board) or backward (toward one's own side) along the file occupied by the piece; and "up" and "down" refer to movement from one board to another.

THE UPPER BOARD

Sylph: The Sylph has a move on the upper board which is essentially the converse of that of a pawn. It moves forward only, one square diagonally either to the left or right, and it can capture a piece on the upper board which lies directly ahead of it by moving forward into that square and supplanting the opposing piece that was located there. Thus, every time a Sylph makes a capture on the upper board, it changes the color of the diagonal along which it makes further (non-capturing) moves, from dark to light or vice versa. Gold's Sylphs begin the game on the light-colored squares of the second rank, while the Sylphs of the Scarlet side start on the dark-colored squares of the seventh rank.

In addition to its movement and capture powers on the upper board, the Sylph can capture an opposing piece on the middle board which lies directly below it. This is the only way in which the Sylph can move to the middle board. It cannot move to, nor make a capture upon, the lower board. Once located on the middle board, the Sylph cannot move except to return to the upper board. It may do this by moving directly upward to the square it previously occupied, or by moving upward to any of the six starting squares for Sylphs of the appropriate color. A Sylph cannot capture by means of an upward move; it must return to the upper board by moving into an unoccupied square.

A Sylph located at 3c4 can move to 3b5 or 3d5. It can occupy 3c5 or 2c4 by capturing an opposing piece, if one is located on either of those squares. After making a capture at 2c4, the Sylph can move back to 3c4 on a subsequent turn, if that square is empty, or it can move up to any unoccupied starting square. For a Gold Sylph, the legal destinations are 3a2, 3c2, 3e2, 3g2, 3i2, and 3k2.

A Sylph that reaches the eighth rank on the upper board can move no farther on that board, but retains the power to capture downward. If such a capture is accomplished, the Sylph can regain mobility on the upper board by moving up into one of the starting squares for Sylphs of the appropriate color.

Diagram, "Sylph (upper board)": a Gold Sylph with M on the two squares diagonally ahead of it and C on the square directly ahead.

Griffon: Starting squares for the Gold Griffons are 3c1 and 3k1; the Scarlet Griffons begin at 3c8 and 3k8. When on the upper board, a Griffon moves one square horizontally or vertically and two squares diagonally. Like the knight, it vaults over intervening squares (even if they are occupied) and only exerts control over the destination square, not the intervening ones. (This is identical to the move of the elephant in Korean chess.) A Griffon at 3d4 can move to or capture a piece at 3a2, 3b1, 3f1, 3g2, 3g6, 3f7, 3b7, or 3a6.

In addition, a Griffon may occupy the middle board by a move down to one of the four squares on the diagonal from the upper-board square it started from. (Note that a Griffon located on the edge of the upper board only commands two squares on the middle board instead of four.) A Griffon returns to the upper board by a move to any of the four (or two) squares diagonally above the Griffon. It can move between the upper and middle boards whether or not a capture is involved. A Griffon at 3d4 can move to or capture at 2c5, 2c3, 2e3, or 2e5.

While a Griffon is on the middle board, it forfeits the power of flight, and as such it can only move and capture in the squares diagonally adjacent to it. A Griffon located at 2e5 commands all of the following squares: 2f6, 2f4, 2d4, 2d6, 3f6, 3f4, 3d4, and 3d6.

Diagrams: "Griffon (upper board)" marks X on the eight squares two files and three ranks away, or three files and two ranks away. "Griffon (middle board)" marks X on the four diagonally adjacent squares.

Dragon: The starting square for the Gold Dragon is 3g1, and the Scarlet Dragon begins at 3g8. A Dragon's movement and capture powers on the upper board are a combination of the moves of the king and the bishop: unlimited along the diagonals, or one square in any horizontal or vertical direction. While the Dragon cannot move downward, it does have the unique ability to capture an opposing piece on the middle board which lies in the square directly beneath it or on any of the squares horizontally or vertically adjacent to that square. The captured piece is removed from the middle board, but the Dragon remains on the upper board. A Dragon at 3c4 could capture "from afar" an opposing piece located at 2c4, 2c5, 2d4, 2c3, or 2b4.

Diagram, "Dragon (upper board)": X along all four diagonals to the edge and on the eight squares around the Dragon.

THE MIDDLE BOARD

Warrior: At the start of the game, the twelve Gold Warriors are positioned along the second rank, and their Scarlet counterparts begin on the seventh rank. The move of the Warrior is identical to that of a pawn, except that a Warrior cannot advance two squares on its first move. The Warrior can move into an unoccupied square vertically ahead of its location, and it can capture an opposing piece located on either adjacent diagonal square ahead of it. The Gold Warrior which starts the game at 2c2 can move to 2c3, or it can occupy either 2b3 or 2d3 by capturing an opposing piece located on one of those squares. A Warrior that reaches the opponent's back rank is promoted to a Hero, in the same fashion that a pawn is promoted. However, unlike standard chess, the owning player does not have a choice; a pawn can be promoted to a queen, bishop, knight, or rook, but a Warrior can only become a Hero. A Warrior cannot move to or capture pieces located on the upper or lower boards.

Diagram, "Warrior (middle board)": M directly ahead, C on the two squares diagonally ahead.

Oliphant: The Oliphants for each side start on the corner squares of the middle board — 2a1 and 2l1 for Gold, 2a8 and 2l8 for Scarlet. The move of an Oliphant is identical to that of a rook — that is, as many squares horizontally or vertically as desired, as long as no piece interferes with its path of movement. An Oliphant cannot move to or capture pieces located on the upper or lower boards.

Diagram, "Oliphant (middle board)": X along the whole rank and file.

Unicorn: The Unicorns for each side start on the squares horizontally adjacent to the Oliphants — 2b1 and 2k1 for Gold, 2b8 and 2k8 for Scarlet. A Unicorn moves and captures in the same way as a knight, including the ability to vault over pieces on intervening squares. It cannot move to or capture pieces located on the upper or lower boards.

Diagram, "Unicorn (middle board)": X on the eight knight squares.

Hero: The Heroes for each side start adjacent to the Unicorns — 2c1 and 2j1 for Gold, 2c8 and 2j8 for Scarlet. On the middle board, a Hero moves either one or two squares in any diagonal direction, with the ability to vault over an intervening piece on a two-square move. Capture is accomplished in the same manner.

A Hero can also move up or down one board at a time, going to any square diagonally adjacent to the square directly above or below its former location. A move back to the middle board is accomplished the same way. When located on the upper or lower board, a Hero's only move is to return to the middle board; it cannot travel to any square other than the one to which it ascended or descended. A move from one board to another can involve a capture if so desired.

Diagram, "Hero (middle board)": X on the squares one and two steps away along each diagonal.

Thief: The two Thief pieces for each side start the game adjacent to the Heroes — 2d1 and 2i1 for Gold, 2d8 and 2i8 for Scarlet. A Thief moves and captures exactly as a bishop, going any number of squares diagonally as long as no piece interferes with its path of movement. It cannot move to or capture pieces located on the upper and lower boards.

Diagram, "Thief (middle board)": X along all four diagonals.

Cleric: The Gold Cleric starts on 2e1, the Scarlet Cleric on 2e8. The basic, two-dimensional move of a Cleric is the same as that of the king: one square in any direction. In addition, a Cleric can move one square directly up or down, and retains its full movement (and capture) abilities on both the upper and lower boards.

Diagram, "Cleric (all boards)": X on the eight squares around the Cleric.

Mage: The Mage for each side starts on the square adjacent to the Cleric — 2f1 for Gold, 2f8 for Scarlet. On the middle board, a Mage moves and captures in the same way as the queen, able to follow an unobstructed path in any horizontal, vertical, or diagonal direction. In addition, a Mage can move (and capture, if applicable) directly upward or downward across one or more boards. However, a Mage on either the upper or lower board is limited to a move of one square in a horizontal or vertical direction. A Mage located at 2c4 could move up to 3c4, and on its next move could go downward two boards to 1c4. If the Mage then remained on the lower board, it could only move to 1c5, 1d4, 1c3, or 1b4.

Diagrams: "Mage (middle board)" marks X along the whole rank, file and all four diagonals. "Mage (upper or lower board)" marks X on the four orthogonally adjacent squares.

King: The King for each side begins on the square adjacent to the Mage — 2g1 for Gold, 2g8 for Scarlet. The King moves and captures similarly to a king in standard chess. In addition, the King may move (and capture) by shifting one square directly up or down. A King which has moved to the upper or lower board cannot move upon those boards, and must return to the middle board before it can again move and capture normally.

Diagram, "King (middle board)": X on the eight squares around the King.

Paladin: The Paladin for each side begins in the square adjacent to the King — 2h1 for Gold, 2h8 for Scarlet. On the middle board, a Paladin's movement and capture abilities are a combination of those of a king and a knight. It can also move upward or downward with a knight-like move, i.e. one board up and two squares horizontally or vertically, or two boards up and one square horizontally or vertically, and it can vault over intervening pieces with this sort of move, just as if the move did not involve a change of boards. Upon the upper or lower board, the Paladin is limited to a king-like move (and capture) of one square in any direction. A Paladin located at 3c4 can move between boards to any of the following squares: 2c6, 2e4, 2c2, 2a4, 1c5, 1d4, 1c3, or 1b4.

Diagrams: "Paladin (middle board)" marks X on the eight squares around the Paladin and the eight knight squares. "Paladin (upper or lower board)" marks X on the eight squares around it.

THE LOWER BOARD

Dwarf: The six Gold Dwarves start on the dark-colored squares of the second rank on the lower board; the six Scarlet Dwarves begin the game on the light-colored squares of the seventh rank on the lower board. Similar to a Warrior, a Dwarf can make a non-capturing move one square vertically ahead, and captures ahead diagonally. In addition, a Dwarf can make a non-capturing move one square in either horizontal direction, and it can capture an opposing piece on the middle board that lies directly above the Dwarf. If a Dwarf moves to the middle board by means of a capture, it retains the movement and capture powers it has on the lower board, but a Dwarf cannot move to or capture pieces located on the upper board. It may return to the lower board by a move directly down to an unoccupied square; i.e., the downward move cannot involve a capture. A Dwarf on 1d4 could move (without capturing) into 1d5, 1c4, or 1e4; it could capture an opposing piece located on 1c5, 1e5, or 2d4. A Dwarf on 2d4 could return to the lower board by moving to 1d4, but only if that square is unoccupied. A Dwarf that reaches the opponent's back rank is limited to horizontal moves on the board it occupies, and also retains the ability to move between the lower and middle boards in the manner described above.

Diagram, "Dwarf (lower board)": M directly ahead and on the two squares beside the Dwarf, C on the two squares diagonally ahead.

Basilisk: The two Gold Basilisks start on 1c1 and 1k1; the Scarlet Basilisks start on 1c8 and 1k8. A Basilisk moves one square at a time, either ahead diagonally or vertically or backward vertically. It captures by forward movement only. A Basilisk also has the unique ability of "freezing" an opposing piece — but not a friendly piece — located directly above it on the middle board, such that the opposing piece cannot move until the Basilisk is moved or captured. (This "freezing" is automatic and involuntary; the player owning the Basilisk cannot choose not to immobilize the piece, and does not have to specifically declare that the "freeze" is in effect.) If the opposing King is the piece being "frozen," the King is checkmated if any other piece attacks it and the opponent is unable to capture the attacking piece or interpose a piece to blunt the attack.

A Basilisk located on 1d4 can make a move or a capture into 1c5, 1d5, or 1e5. It can move to 1d3 if that square is unoccupied, and it automatically "freezes" any opposing piece on 2d4, or one that is subsequently moved into 2d4. A Basilisk cannot move off the lower board or (with the exception of the "freezing" power) capture a piece on any other board.

Diagram, "Basilisk (lower board)": X on the three squares ahead of the Basilisk, M on the square behind it.

Elemental: The Gold Elemental starts on 1g1; the Scarlet Elemental begins the game on 1g8. An Elemental can move one square diagonally or one or two squares horizontally or vertically. It captures only on horizontal or vertical moves. It may move up to the middle board to make a capture by moving one square horizontally or vertically and then directly upward. It may remain unmoving on the middle board if so desired, or it can return to the lower board by a reverse of the upward move, i.e., directly down and then one square horizontally or vertically. The upward move can only be made if a capture is involved, but the downward move can be made without capturing.

An Elemental on 1d4 can move (but not capture) into 1c5, 1e5, 1e3, or 1c3. It can move or capture into 1d5, 1d6, 1e4, 1f4, 1d3, 1d2, 1c4, or 1b4. It can capture upward into 2d5, 2e4, 2d3, or 2c4. An Elemental on 2d4 can move or capture downward into 1d5, 1e4, 1d3, or 1c4.

Diagram, "Elemental (lower board)": X on the first and second squares in each of the four orthogonal directions, M on the four diagonally adjacent squares.

Movement between boards

At first, it may be difficult for players to envision and properly execute the upward or downward movement of pieces. However, "thinking in three dimensions" will come easily after one or two practice games are played. Perhaps the hardest single concept to grasp is the idea of intervening squares on moves from one board to another. The general rule is this: If a piece is unable to vault over intervening squares in its basic (two-dimensional) move, then it is likewise unable to move between boards if a piece blocks the path it must take. Specific applications for particular pieces are as follows:

The Griffon, the Hero, and the Paladin all have the knight-like ability to vault intervening squares, and this applies on any upward or downward move made by those pieces. (The square directly above or below the piece in question need not be vacant.)

The Mage can move from the lower board to the upper board (or vice versa) in a single move, but it cannot vault intervening squares. Thus, in order for the Mage to travel upward from 1d4 to 3d4, the square at 2d4 must be vacant.

The Elemental is something of a special case. Its move between boards is a two-step process, and it cannot vault over intervening squares. Its upward move begins with a shift of one square horizontally or vertically on the lower board; thus, at least one of the squares horizontally or vertically adjacent to the Elemental must be vacant in order for it to make an upward move. The Elemental is even more restricted when moving down from the middle board; since the horizontal or vertical move is preceded by a move directly down, the square immediately beneath the Elemental must be vacant in order for it to make a downward move.

Chess rules that do not apply

Two conventions of standard chess are not part of the DRAGONCHESS rules. The Warrior is unable to move two squares ahead on its first move, and as such it is not possible for a Warrior to capture en passant as a pawn does. Also, because of the multiple boards, greater area of play, and larger number of men, castling is not possible in DRAGONCHESS.

Values of the pieces

The complexities of multiple-board play and the varying powers of the pieces in DRAGONCHESS makes absolute valuation far more difficult than it is for standard chess pieces. In chess, a pawn is valued at 1, knights and bishops at 3, rooks at 5, and the queen at 9. (If the king were not of infinite value, its movement and capturing power would give it a value of 4.) The approximate relative values of the pieces in DRAGONCHESS is detailed below, to give players an idea of which exchanges are beneficial and which are not. For instance, the trade of a Hero for a Griffon is roughly an even exchange, while the trade of a Basilisk for an Oliphant will generally result in a material advantage for the player losing the Basilisk. However, it should always be kept in mind that the true "value" of a piece in any game situation depends primarily on the piece's location and its role in the game, rather than on its theoretical movement and capture powers.

Piece	Value	Piece	Value
King	**	Thief	4
Mage	11	Elemental	4
Paladin	10	Basilisk	3
Cleric	9	Unicorn	2½
Dragon	8	Dwarf	2
Griffon	5	Sylph	1
Oliphant	5	Warrior	1
Hero	4½

** — In practice, the value of the King is infinite, since the loss of this piece means the loss of the game.

Movement and capture notation

The method of recording moves in DRAGONCHESS is basically the same as for standard chess, with certain differences (explained earlier) to account for the different names of the pieces and the multiple boards. The following examples cover all the situations that could occur in a game:

1. W2f3
2. S/3e2-3d3

A basic non-capturing move; notation 1 is the first non-capturing move that the Gold Warrior starting at 2f2 can make. (Read it as "Warrior moves to 2f3.") In most cases, a non-capturing move can be noted simply by naming the type of piece being moved (W) and the square it moves to (2f3). When more than one piece of the same type is capable of making the same move, the moving piece is specifically identified by naming the square it is moving from, using a "/" to indicate "at." (Read notation 2 as "Sylph at 3e2 moves to 3d3.") In this notation, a hyphen is used to separate the location square from the destination square.

3. W2e3
4. Wx2e3
5. W/2d2x2e3
6. WxU2e3
7. WxU

Five ways of describing a capture; the correct notation depends upon the position of the pieces and, to some extent, the preference of the players. Notation 3 can be used if only one Warrior is capable of moving to 2e3, and if that move involves a capture. Notation 4 is more specific, using the "x" to indicate a capture. (Read as "Warrior captures (unspecified piece) at 2e3.") Notation 5 is necessary when more than one Warrior would be capable of making a capture at 2e3, again using the "/" (as in notation 2 above) to indicate "at." (Read as "Warrior at 2d2 captures at 2e3.") Notation 6 includes the identification of the type of piece captured — in this case, the Unicorn located at 2e3. Notation 7, read simply as "Warrior captures Unicorn," can be used if only one such capture is possible. In most cases, the proper notation would be 4, 5, or 6, or a minor variation on one of those. The important thing is to describe each move in such a way that the notation could only refer to one specific move by one specific piece. This will avoid possible confusion if the moves of a game are to be studied or replayed.

8. W2f8(H)

The move and promotion of a Warrior. (Read as "Warrior moves to 2f8 and is promoted to a Hero.")

9. Drx2c4

A capture "from afar" by a Dragon. (Read as "Dragon captures (unspecified piece) at 2c4.") To avoid the awkward "Drx" usage, this move could be written as "Dr2c4" since any move by the Dragon involving a square on the middle board must necessarily be a capture "from afar."

10. UxOch

Illustrating the use of "ch" to indicate a move that puts the opposing King in check. (Read as "Unicorn captures Oliphant with check.")

Other symbols: dbl ch, dis ch, mate

These three terms, taken from standard chess notation, indicate certain special occurrences. Double check (dbl ch) occurs whenever a move enables one or more pieces to give check at the same time. Discovered check (dis ch) occurs when the move of one piece opens a path that enables a different piece to give check. And "mate," of course, is checkmate — noted on the final move of a game, when the King is attacked in such a way that it cannot avoid being captured on the attacker's next move.

No special notation is given for the Basilisk's "freezing" power, since it is not technically a move or a capture, and since it is automatically assumed that any piece occupying the square above the Basilisk is frozen. Thus, a notation of B1e3 makes it clear that (a) the Basilisk now occupies square 1e3 and (b) any opposing piece located at 2e3 is thereby immobilized as long as the Basilisk remains where it is.

Strategic and tactical tips

No single piece of text — even one many times longer than this — could fully describe and analyze the myriad positions and situations that can occur in DRAGONCHESS. However, some general strictures are apparent from an examination of how the various pieces move and capture, and certain basic facts of chess strategy apply equally to DRAGONCHESS.

Mobility is all-important, and, just as in chess, control of the central squares is usually a prerequisite for victory. The rectangular board of DRAGONCHESS makes the "central squares" area somewhat more difficult to define than it is in chess — but it certainly is a larger area. It could be described as a 2x6 rectangle with 2d4, 2d5, 2i5, and 2i4 as its corners; or, a 2x8 rectangle extended out on either side; or, a 4x4 rectangle in the center of the middle board. In any event, the side that does the better job of controlling the center squares will have a greater amount of mobility and will more easily be able to bring pieces to bear upon critical squares anywhere on the playing surfaces.

In many instances, the square that a piece stands on is not as important as the squares that the piece controls. Players should be mindful of moving their pieces into positions where they command a large number of squares, thereby limiting the opponent's ability to occupy those same locations.

In general, it is wise not to bring the "big guns" (particularly the Mage and the Paladin) into active positions until some of the minor pieces have been developed. Making a lot of moves with the Mage (for instance) early in the game is usually a bad idea, because this delays the development of other pieces that could have been moved out instead, and because this could subject the Mage to a series of harassing attacks from the opponent's minor pieces — which are being developed at the same time that they are doing the harassing. (In chess, this phenomenon is known as a "queen hunt," and it has led to the downfall of many a player who had visions of ravaging the opposition with sweeping moves of the queen — but instead ended up without a queen to move.)

It is no accident that each side's Dragon begins the game directly above the King of the same side. While the Dragons are obviously powerful offensive pieces, each must play predominantly a defensive role to begin with — for if one Dragon sallies forth on the upper board to wreak havoc upon the opponent's middle-board pieces, the King may be left vulnerable to a quick but deadly attack from the opposing Dragon.

The power of the Basilisk to immobilize an opposing piece has a lot of potential for use in offensive and defensive strategy. To help protect one of your own pieces, move it to the square above one of your Basilisks. Then, if it is captured, the capturing piece is "frozen," and you can capture it more or less at your leisure without necessarily having to make the return capture immediately. A well-timed Basilisk move can lead to an abrupt checkmate even if the opposing King is not the piece that is frozen, in a case where the Basilisk immobilizes a piece that was crucial to the defense of the King. Except for the fact that it occupies a square on the board, an immobilized piece can be treated as if it did not exist. An immobilized Mage may be better than no Mage at all — but not by much.

In general, the pieces on the lower board (especially the Dwarves) do not play critical roles in the opening or the middle game, but if the Dwarves haven't already been moved too far forward, they can be very useful in the endgame (when relatively few pieces remain on the board) as defensive outposts, to prevent the opponent's middle-board pieces from penetrating too deeply into the territory nearest your side of the board.

Do not underestimate the power of the Cleric. Of the five types of pieces that can move up or down to any of the three boards, the Cleric is the only one which moves and captures in the same fashion regardless of which board it occupies. The Paladin and Mage are limited in their mobility when not on the middle board, to such an extent that they will not generally spend much time on the upper or lower board — and the Heroes and the King, although they can move to the upper or lower board, cannot move on those boards, and the King especially can be easily trapped if left on the upper or lower board for any longer than necessary.

Putting together a game

For reasons that should be obvious, this presentation could not include actual components for a DRAGONCHESS game — making a board and filling it with pieces must be left up to you. For our playtesting and development purposes, we constructed a board from sheets of plexiglass with contact paper applied to form the checkerboard patterns. The boards were spaced approximately six inches apart, allowing enough room for hands to reach in and manipulate pieces. The squares on our board are 1½" on a side, making a playing surface 18" wide and 12" deep. The plexiglass sheets were cut large enough to allow another 1½" all around, and had ¼" holes drilled in each corner. Through these holes we inserted threaded metal rods, fastened into place with connectors to space the boards properly and capped on each end with plastic knobs to prevent scratching the surface on which the entire board is placed during play. It probably isn't necessary to build a three-dimensional board; three flat rectangles placed in a row on the tabletop could be used to represent upper, middle, and lower levels. But it's a lot easier to visualize the up-and-down moves of pieces if the playing surface is actually composed of three levels.

The pieces came from our collection of metal miniatures, and they do not in all cases exactly resemble the pieces they represent. (For instance, we used centaur figures for Oliphants because we couldn't find any 25mm scale elephants — and even if we could have, they would have been too large for the board.) Any sort of pieces will do, even simple tokens, as long as each type of piece looks distinctly different from the others.

Good luck, and may all your moves be ones that Rexfelis would envy. . . .

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Decisions

Where the text contradicts itself, leaves a case open, or needs a rule chess players take for granted, the engine does the following. Each is a reading of the text above, not a change to it, except the two marked as options the host may choose.

1. Board numbers. The notation paragraph makes the upper board 1 and the lower 3, but every piece description, every example and the diagrams' labels use 3 for the upper board and 1 for the lower (the Griffons start at 3c1, the Dwarves on 1d4, the Elemental on 1g1). The engine and every page use 3 for the air, 2 for the land and 1 for the underworld. Wikipedia's article and the Chess Variant Pages' second article read it the same way.
2. The Thieves. The "Setting up" paragraph lists the middle board's pieces without the two Thieves. The diagram shows them on d and i, the Thief has its own entry, and the count of 42 a side needs them. They are in.
3. Light and dark. With a light square in Gold's near right corner, square l1 is light and a1 dark. Gold's Sylphs therefore start on a2, c2, e2, g2, i2 and k2 and Scarlet's on a7, c7, e7, g7, i7 and k7 (the same files, as the diagram shows); the Dwarves start on b, d, f, h, j and l of their second rank.
4. Captures on board-changing moves. The text says "move" for the Mage's step on the upper or lower board, for the Paladin's knight-like move between boards, and for the Cleric's and the King's step up or down, and says "move (and capture)" or "move or capture" elsewhere. The engine lets every one of those capture, since the text forbids capture only where it says so (the Sylph's return upward, the Dwarf's move down, the Elemental's diagonal step, the Basilisk's step back). The Mage's "limited to a move of one square" is read as a limit on distance. The King's return to the middle board may capture.
5. Blocked vertical moves. The Mage's move up or down two boards needs the square on the middle board vacant. The Elemental's two-square orthogonal step needs the square between vacant, as the general rule says. The Elemental's move up needs its first, sideways square vacant and the square above that to hold an enemy; its move down needs the square beneath vacant and lands by a further orthogonal step, with or without a capture.
6. The Dragon's capture from afar is a whole move. The Dragon stays where it is and the piece below or beside-below is removed. It attacks those five squares for the purposes of check.
7. A frozen piece cannot move, capture or give check, and protects nothing. "An immobilized piece can be treated as if it did not exist", except that it still occupies its square. A frozen King attacked by another piece is in check and may be rescued only by capturing the attacker or interposing.
8. Check, checkmate, stalemate, repetition. As in chess: a move may not leave one's own King attacked, a King attacked with no escape is mated and the game is lost, a player with no legal move and not in check is stalemated and the game is drawn, and a position seen three times with the same side to move is a draw. The text names only checkmate; the other endings follow "as in standard chess".
9. Promotion happens the moment a Warrior arrives on the far rank, to a Hero, with no choice. A Sylph on the far rank keeps its downward capture and comes back to life by moving up into a vacant home square. A Dwarf on the far rank keeps its sideways moves and its moves between boards.
10. The Sylph's return from the middle board is to the square directly above it, or to any vacant one of its own six home squares, without capture.
11. Option, the Sylphs' files. As printed, Gold's Dragon on g1 looks along the diagonal to a7 and can take Scarlet's Sylph there on the first move, with nothing defending it. Jean-Louis Cazaux suggested on the Chess Variant Pages that the Sylph rank was misprinted and belongs on b, d, f, h, j and l like the Dwarves beneath them, which closes the diagonal with one change. The host may choose "as printed" or "Sylphs shifted". The printed setup is the default.
12. Option, which side you play. Gold moves first.