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This page is written by the game's inventor, Charles Daniel.

Holy Grail

The game is played on the same 104 square board used for games such as Birds and Ninjas and Stealth Ninja Chess. It uses a pair of modified Templars from Templar Chess and a pair of Champions from Omega Chess. The knights are augmented with either a Ferz (diagonal stepping) or Wazir (orthogonal stepping) movement.

The game can be played with these pieces alone, but the crux of the game features the pieces introduced through drop zones.
Like in Stealth Ninja Chess, 4 ninja pawns can enter the game (one on each turn) via any empty square in 2nd rank.
Two additional pieces can be dropped into an empty space in one of the 2 rear edge squares: the Crown Prince, and the Mutating Serpent. Dropping each of the above pieces is considered a move.
It is advisable to play with at least the very interesting Mutating Serpent.

The mutating serpent must morph into one of several pieces, the default set being the Stealth Gryphon, the Anti-Gryphon, the Flying Bomber, the Raptor, the Cannon, and the Vao. Instead of moving during a turn, a side can make the Serpent mutate into another piece. This piece must be dropped as one of its mutated forms.

Once a side drops the Prince into the game, the opposing side cannot win by just checkmating the king. This is because the checkmated king will demote itself to a ninja pawn and the prince will take over as king! Thus this new king must be checkmated to secure a win. However, the prince can only become king if it is not currently under attack.


Holy Grail Start position

Coordinates for white. (black mirrors white)

Champions on a1,j1
Rooks on b1,i1
Wazir Knight on c1
Ferz Knight on h1
Bishops on d1, g1
Queen on e1
King on f1
Battle Templars on e0,f0
Pawns from a2-j2


The Battle Templar

The Battle Templaris a color bound piece that can move one or leap two steps diagonally or leap 2 squares orthogonally. It can capture by replacement only on the square it lands. Note that it cannot move 1 step orthogonally.

The Champion (or Alfil/Wazir/Warmachine)

The Champion can move one or leap two steps orthogonally or leap 2 squares diagonally. It is the exact inverse of the Battle Templar. It can capture by replacement only on the square it lands. Note that it cannot move 1 step diagonally.

The Champion is not original to this game and was developed for Omega Chess.

The standard pawn

Moves exactly as in standard chess except:
The pawn can move from its original position either 1, 2 or 3 vacant squares forward. If it moved only 1 space originally or captured from original position, it can move forward two spaces towards the center.
see rules for more info.

The Ferz-Knight

  1. It can move one diagonal step in any direction.
  2. It can leap to any path traced out by one diagonal square followed by one orthogonal square outwards (135 degrees angle).
  3. It captures on the square it lands. Leaped over pieces are unaffected.

The Wazir-Knight

  1. It can move one orthogonal step in any direction.
  2. It can leap to any path traced out by one orthogonal square followed by one diagonally outwards (135 degrees angle).
  3. It captures on the square it lands. Leaped over pieces are unaffected.
*Note that the Wazir-knight and the Ferz-knight both leap to the same square like a standard knight.


While the above pieces alone can be used for a satisfactory game, play is enhanced by invoking the Drop Rule and dropping 4 Ninja Pawns, the Crown Prince and the Mutating Serpent that mutates to the: Stealth Gryphon, Anti-Gryphon, Flying Bomber, Raptor, Cannon and Vao. Drop Zone for Ninja Pawns: white - a2-j2   black - a9-j9.
Drop Zone for other pieces: white - e0 or f0   black - e11 or f11.

The Crown Prince

White Prince Black Prince The Crown Prince moves and captures exactly like a king: one step in any direction.
It can be captured just like a normal piece.
It is coronated only if the King is checkmated and it is not under attack.

The Ninja Pawn

The ninja pawn possesses slightly different modes of movement and capture depending on which half of the board it is on.
The ninja pawn can always move 1 square up or 1 square sideways to an empty square from any part of the board.
When the pawn is situated in the lower half of the board (for White, rank 0-5 and for black 11-6), it can move forward multiple vacant squares (1-3 squares) to reach the middle of the board (rank 5 for White or rank 6 for Black). This move can be done at any time regardless of how many times the pawn has moved.
Once it passes the middle, the ninja pawn can only move 1 square forward at a time, or move 1 square horizontally.
Like the standard pawn it can capture one square diagonally up, regardless of which half of the board it is on.
When the ninja pawn is on the top half of board (White rank 6 +, Black rank 5-) , it can also capture one square horizontally.
There is no en passant. It cannot capture another pawn or ninja pawn en passant nor can any other pawn capture it this way.
Promotion: The ninja pawn promotes on the last row (rank 10 for white, rank 1 for black), to any piece. Promotion to a piece is mandatory so it would cease to be a pawn in the last row.

The ninja pawn is not present at the start at the game and is dropped by the player into the drop zone, which are the 2nd rank squares. For example, the drop zone for white is a2-j2 and for black a9-j9.
The square must be vacant to drop the pawn. You can drop a pawn to check or to checkmate the opposing king A maximum of 4 ninja pawns can be dropped by each side during a game.
After dropping a pawn, the player can optionally move the ninja pawn forward 1 or multiple squares towards the center on the same move. A capture or a side move is not permitted during the drop, so the player can drop a pawn and pass, or drop a pawn and move it 1-3 vacant squares towards the center.

In diagram, the black ninja pawn can go from e9-e6 or any other square in between or d9 or f9. The white pawn at f7 cannot capture it en passant

Lets say the white ninja pawn went from e3-f3 , it still has the option of shooting forward to the middle (f5) regardless of how many moves it made before.

The white ninja pawn at h9 can capture the bishop at i9 in addition to being able to go to g9 or to promote by going to h10.

The Mutating Serpent

Like a serpent that sheds its skin, only more drastic, this piece can take the shape of any of the following pieces: Stealth Gyrphon, Anti-Gyrphon, Vao, Cannon, Flying Bomber and Raptor.
It can only mutate during its side's turn, and mutating counts as one move.
It never reveals its true face, and must take the shape of another piece when dropped. The drop counts as one turn. (It cannot move on the same turn when dropped)
Additionally, it must make at least one move with its current mutation before it can transform again.. e.g. The Serpent just transformed into a Raptor from something else. The raptor must move first before it is allowed to mutate again.
There is no restriction on when the serpent mutates as long as it moved at least once with current mutation.

The Stealth Gryphon

The Stealth Gryphon is a potentially powerful piece that can control multiple files and ranks if used effectively, and its awkward move can catch an unsuspecting opponent by surprise.
Movement/Capture by replacement: It must move along any unobstructed path (it cannot leap) of 1 square diagonally followed by 2 or more squares horizontally or vertically outwards. Thus, it can reach its destination square only one way but it can exert a powerful influence when not blocked.
The Achilles heel of the Gryphon (and the Anti-Gryphon) is its susceptibility to having its path blocked, and its vulnerability to close range attack.
Partial board shows white king on e0 and black Stealth Gryphon on h1. Red is "offboard".

Here the griffon is hampered by the edge of the board but still exerts great influence.
It controls the squares in yellow but it is not checking king because it needs to go one diagonal first and then 2 or more orthogonal outwards and there is no such path towards the king.

The Stealth Anti-Gryphon

The Stealth Anti-Gryphon is the exact inverse of the Stealth Gryphon, and so controls multiple diagonals.
Movement/Capture by replacement: It must move along any unobstructed path (it cannot leap) of 1 square horizontally or vertically followed by 2 or more squares diagonally outwards.
Partial board shows black Stealth Anti-Gryphon on e4. Note that it will control more squares on the actual board.

Anti-Gryphon shown controls the squares in yellow. Notice its long-range prowess but short-range vulnerability. Esp note how easily a piece can block its path.

The Flying Bomber

Movement: When not capturing it moves exactly like a rook (1 or more squares orthogonally over a clear path).
It can also jump two squares orthogonally by leaping over an adjacent piece.
Capturing: The flying bomber eliminates an enemy piece by flying towards it in a unobstructed orthogonal path, and landing on THE empty square immediately after it. It cannot capture if this square is occupied nor can it capture a second piece.
The exception to above: the flying bomber can capture by replacement any enemy piece that is 2 squares away. Thus, it can jump over a friendly piece to make a capture 2 spaces away.
If, instead, there is one empty square between the Flying Bomber and the enemy piece, the Bomber can either capture by landing two squares away on the target's square or use the standard method of capturing by landing on empty square immediately after target.
If there is one enemy piece adjacent to it and another immediately after on same line, the flying bomber combines both capture mechanisms to makes a double capture as it lands 2 squares away. Note that when it makes this jump under above conditions capturing both pieces is mandatory.

The Raptor

The Raptor is an exact diagonal version of the Flying Bomber.
When not capturing, it moves exactly like the bishop.
To capture, it flies towards its prey along an unobstructed diagonal path and lands on the square immediately after it.
Additionally, like the Flying Bomber, it can make a special move by jumping over a diagonally adjacent friendly piece.
Similarly, it can also capture by landing on the same square as an enemy piece exactly two square away diagonally.
If an empty space separates the Raptor from its prey, then it can capture by replacement on target's square, or if possible, capture by landing on the empty square immediately after.
If there is a friendly piece between the Raptor and its prey, the Raptor can only capture by replacement.
If there is one enemy piece adjacent to it and another immediately after on same diagonal line, the raptor takes out both pieces and lands 2 squares away.

The Cannon

Movement: When not capturing the Cannon moves like a rook.
Capturing: The Cannon as in Xiangqi needs an intervening piece called the screen to make a capture. The screen can be either a friendly or enemy piece and must lie between the cannon and the target enemy piece for a capture to take place.
The Cannon captures the enemy piece by leaping over the screen and landing on the target's square.

The Vao

White Super Vao Black Super Vao The exact diagonal equivalent of the Cannon. Moves passively like bishop, jumps over screen to capture enemy piece.


The rules in Holy Grail are the same as in chess except for the following modifications :
  1. Castling: The usual castling criteria apply: No piece can be situated in the spaces passed over by the king and castling rook, cannot castle out of check, King cannot pass over or land on squares attacked by enemy, but rook can.
    Castling is flexible with the king able to travel 1,2, 3, or 4 squares towards the rook, while the rook moves over the king to the adjacent square. Note that the rook must always be next to the king after castling.
    There are 7 possible castling positions, the most extreme wing castling being the king going to the b or i file while the rook slides just one step towards the center.
    The choice of castling positions will depend on whether it is immediately necessary for the king to be nearer the wing or for the rook to be centralized.
  2. Pawn moves: A pawn situated on the lower half of the board can at any time move forward 1-3 vacant squares to reach the center of the board (rank 5 for white, rank 6 for black). Once the pawn reaches the center row, it can move forward only one square at a time.
    Some examples: The white pawn at f2 can start f2-f5 or it can move f2-f4 then f4-f5, or f2-f3 followed by f3-f5, or move f2-g3 to capture enemy piece at g3 followed by g3-g5 next time it moves.
  3. En Passant: If a Pawn moves two or three squares initially and passes an opposing Pawn on the fourth or fifth rank, the Pawn may be captured en passant. E.g. White pawn on a2 black pawn on b4. If the white pawn moves from a2 to a4 or a5, the black pawn on b4 can capture it as if it had moved to a3. Similarly, if the black pawn is on b5 instead and the white pawn moves to a5 from a2 then the black pawn can capture the white pawn as if it moved to a4. Note in this case the white pawn can still avoid the black pawn by moving to a3 instead.
    If a pawn slides forward 2 squares on its second move, it can also be captured en passant by an opposing pawn on the fifth rank. E.g. white pawn on a3 and black pawn on b5. White plays a3-a5, black pawn on b5 can capture the pawn en passant by moving to a4.
    Capturing en passant is optional unless it is the only legal move available. The capture must be made on the next move.
  4. Pawn promotion: Pawns can now promote to: Queen, Bishop, Knight, Rook, Templar, Champion, Prince or Serpent on the 10th rank only. Note that if promoting to Serpent, it must become one of its mutating forms . If a player promotes to another Prince then that too will have to be checkmated if it Crowns successfully.

Reinforcements - Dropping pieces

Players must decide beforehand which pieces they want to drop, and what the serpent mutations should be:
4 ninja pawns, a Prince and a Serpent Mutator.
4 ninja pawns, and a Serpent Mutator. In this case, the Crown Prince and its associated rules do not apply.

OR some of the options and wilder mutations described at the bottom of this page.

Crowning the Prince / Winning Conditions

Just as in chess a side wins by checkmating the opposite king. This still holds as long as the opposing side has not dropped the prince or if its prince has been captured.
If however, there is an un-attacked prince on board, then that side will demote its king to a ninja pawn and promote its prince to a king. This crowning process constitutes one move for that side, and now this new king has to be checkmated by the opposite side.
The only way around this is to checkmate the king before the prince is dropped, to capture the prince prior to checkmate or to checkmate the king and attack the prince simultaneously.

The Demoted Ninja Pawn

The demoted ninja pawn will attain its usual powers depending on its location. Therefore if the king is checkmated on the upper half of the board, the ninja pawn can capture sideways.
If the king is checkmated on the promotion zone, the ninja pawn can only promote on its next move and it MUST make a move or capture to promote. Thus, a king now demoted to ninja pawn on d10 must move/capture on next turn to c10 or e10 or make a capture on e11 to promote. A ninja pawn can promote on the squares e11, f11 or e0, f0 under these special circumstances if it can get there. Normally this is impossible since the pawn must promote on the 10th rank, but now the checkmated king on say e10 becomes a ninja pawn and on next turn moves to e11 to promote.


IF the king is stalemated then it is a draw just as in orthodox chess regardless of if there is a prince on board or not.
If the king is checkmated, and the Prince is crowned, then if on the next turn (Crowning the prince is one turn), the newly crowned King cannot move without being captured, then it is stalemate (as in usual rules) and the game is drawn. Note though that the attacking side gets another turn after the checkmate.


It is advisable for players to start of with the recommended pieces with ability to drop 4 ninja pawns, Prince and Serpent that mutates to Stealth Gryphon, Anti-Gryphon, Super Vao, Super Cannon, Flying Bomber and Raptor.
Once familiar with the game, the alternative pieces can be also be tried to produce very interesting gameplay.
The Crown Prince /checkmate 2 kings rule does not need to be invoked, and instead players can just drop 4 Ninja Pawns and the Serpent. This seems to be the most exciting alternative to the main variant.
Other possibilities include: Dropping 4 ninja pawns only or playing with no drops at all.

Alternative Mutations

For a wilder game, the following mutations can be used to in addition to the default set.

The Super Cannon /Super Vao

These pieces extend the movement of the Cannon or Vao. In addition to moving passively like a Rook, The Cannon can also jump over an adjacent friendly piece to land 2 squares away. Note that it cannot jump over an enemy piece in this manner.
The Super Cannon like the Cannon in Xiangqi needs an intervening piece called the screen to make a capture. However, if the screen is an enemy piece then the firing mechanism of the Super Cannon is altered to destroy both its target and the screen at the same time! Thus, it takes out both enemy pieces after it lands on the target enemy piece's square.
The Super Vao is the diagonal equivalent of the Super Cannon.

Full Powered Gryphons

Instead of the Stealth Gryphon and Anti-Gryphon, the fullpowered versions of those pieces can be used. For example, the Gryphon can move to 1 step diagonal and/or any number of orthogonal spaces outwards. Similar for the Aanca - the full version of the Anti-Gryphon.

Insane Ninja

The Insane Ninja possesses both dual mode movement and dual mode capture capabilities.

Insane Ninja Ice Queen

This piece move exactly like Insane Ninja above but it also possesses the power to freeze any piece that comes within its range.

The Buffalo

The Buffalo moves in three ways, capturing on the square it lands:

Alternative Setup

The templars and champions can switch positions- thus the champions will occupy the rear squares and the templars will occupy the wing positions.

This 'user submitted' page is a collaboration between the posting user and the Chess Variant Pages. Registered contributors to the Chess Variant Pages have the ability to post their own works, subject to review and editing by the Chess Variant Pages Editorial Staff.

By Charles Daniel.
Web page created: 2008-04-24. Web page last updated: 2008-08-14