The Chess Variant Pages

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

Prison Break

This is an entry in the 45/46 cell 2007 design contest.

The game is played utilizing 46 squares of a chessboard, and new unique pieces, all of which can be represented by the standard pieces.

The game situation is a prison with two opposing sides, each of which tries to either checkmate the opposing king, or to enable its king to escape by reaching the squares a4 or a5 safely. A king cannot flee the prison if the escape squares are controlled by the opposing piece (i.e. the king can be captured), so even though the two squares a4 and a5 are not occupied by any piece, they play an important part in the game.


The standard chess pieces can be used to represent the new pieces.
Queen=Ice Queen
Bishop=Ninja Guard
Rook=Flying Bomber
Prison Break starting position Start Position for white. (black mirrors white)

Flying Bomber on a1
Knight on b1
Ninja Guards on c1, f1
Ice Queen on d1
King on e1
sliding pawns from a2-f2


The Ice Queen

Things get even more complicated because of the presence of the beautiful but deadly ice queen.
She moves one step in any directionjust like the king, capturing if possible, but any enemy piece including the king that is attacked by her is frozen and cannot move!
    Ice Queen Rules
  • Any piece that moves into her range will be frozen!
  • Pieces can move through her range though. E.g. a flying bomber can pass adjacent to her and as long as it does not land within range it will be unfrozen
  • To attack an ice queen, the attacking piece must be at least two squares away and thus safely out of her range.
  • Consquently, an ice queen cannot attack another ice queen because it becomes frozen first.
  • Frozen pieces CANNOT move or attack another piece neither can they deliver check.
  • A piece can only be unfrozen if the hostile ice queen is captured by another piece or if the ice queen moves away.
  • As soon as a piece is unfrozen it can attack another piece or deliver check. Thus in some cases, the ice queen may be pinned by the frozen piece!
  • An Ice Queen can capture any piece in its vicinity just like a king does. The only difference is that the captured piece is already frozen.
  • A simple check by an Ice Queen can lead to checkmate if the Ice Queen cannot be captured.
    NOTE that a king can NEVER capture an ice queen since it will be already frozen if within her vicinity.
Ice Queen Moves Frozen Delimma!

In this position black must move the king away by one step because white is threatening checkmate with: e5-e6 or e5-f6. White cannot play e5-d6 because its Ice Queen will become frozen. Note that black's best move is e7-d8. This move is NOT illegal since the pawn is frozen and cannot attack the king.

Black on the other hand has frozen both the flying bomber at c5 and the pawn at c7. In addition to the checkmate threat, white has imposed a strange pinning predicament on black.
If the ice queen takes the flying bomber than white can promote the pawn. Similarly, if the ice queen captures the pawn then white flying bomber can capture the ice queen at c7.

The Ninja Guard is a color bound piece that can move one step or jumps two steps diagonally. It can capture on square it lands as well as capture by jumping over, so it could capture two pieces in one move.

The Flying Bomber moves exactly like a rook when not capturing, and captures by flying over (or overtaking) a piece and landing immediately on the empty square after it on the same orthogonal line. There must be an empty square after the piece. If there is another piece right after, then it cannot capture.
This is a special maneuver that enables the Flying Bomber to fly over the adjacent square, (jumping over, if occupied by friendly piece or eliminating if occupied by enemy piece) and land like a helicopter on a square exactly 2 squares away, capturing if possible on this square. Thus, it can capture two pieces in this manner.

see Birds and Ninjas for a detailed description with diagrams of the above two pieces.

The sliding pawn moves and captures exactly as in orthodox chess except for the following. Normally, when a pawn faces an opposing pawn or an enemy piece, the pawn is blocked. However, the sliding pawn can, under these circumstances only if it is blocked, slide pass the enemy piece or pawn with the same 1-step diagonal movement that it would make when capturing.


The rules are as in orthodox chess except as noted below:
  • There is no castling.
  • In addition to checkmate, a side can also win if its king can flee to the squares a4 or a5.
  • An Ice Queen can checkmate by merely checking (see Ice Queen moves).
  • The unused squares (a4,a5) do not hinder the movement of any pieces. A piece can prevent a king from escaping to a4 or a5 by capturing even if it must land on a4 or a5 to capture the king. E.g. Black flying bomber on a7 prevents white from moving king to a4 since a7-a3 is threatened or to go to a5 since a7-a4 is threatened.
  • Pawns promote on the last rank to Ice Queen, ninja-guard, flying bomber or knight.
  • All rules governing draws including stalemate are exactly as in orthodox chess


The Ice Queen was inspired by Sub-Zero of Mortal Kombat. In the famous arcade game, this shady character would freeze his enemy to ice, and then shatter his enemy to pieces with a strike.

The Ice Queen is also very similar to the Medusa in Pillars Of Medusa.
It also resembles the Immobilizer in Ultima
Subconscious inspiration is a possiblity.

On a more humorous note, the Ice Queen bears some resemblance to the infamous Tonya Harding, an ice skater who hired a henchman to take out the knees of her rival Nancy Kerrigan.


Play Prison Break!

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: 2007-11-08. Web page last updated: 2007-11-08