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:

Attribute	Effect
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, but can be destroyed.
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.