Notation

Movement

The movements of chess pieces can be generally described by this formula:

a(m/n)

Where m is the distance 'leaped' on one axis and n is the distance 'leaped' on the other, and a is the number possible leaps performed in a single ply in one direction. If the letter 'n' is given for any number it denotes unlimited.

The standard chess pieces can therefore be described with this notation as such:

Piece	Movement
Knight	1(1/2)
Bishop	n(1/1)
Rook	n(1/0)

Where a value of n for a represents an infinite number of moves. Pieces can combine movement types as well:

Piece	Movement
Queen	n(1/1), n(1/0)
King	1(1/1), 1(1/0)

Where combined movement types are separated by a comma. Some pieces have special conditions attached to their movements:

• i - May only be made on the initial move.
• c - May only be made on a capture.
• o - May not be used for a capture.

Additionally, some moves are restricted by direction:

• > - May only move forwards.
• < - May only move backwards.
• = - May only move sideways.

Thus the Pawn, being the most complicated standard piece, can be described as such:

Piece	Movement
Pawn	o>1(1/0), oi>2(1/0), c>1(1/1)

Piece Attributes

Some of the pieces in Fortress have zero or more attributes associated with them:

• royal - All royal pieces on the opposing team must be captured to win. In standard Chess there is only one royal piece, the King.
• ranged - Capturing moves are made without moving, that is ranged pieces capture from a distance without leaving their square.
• invincible - Cannot be captured, except by exploding pieces.
• hidden - Invisible to the other player except when it is in the sight-line of one of his or her's pieces. That is to say, if a piece on the opposing team can capture a hidden piece, it is visible, otherwise it is invisible, except on the first ply.