Hippogonal
A hippogonal chess move is a leap m squares in one of the orthogonal directions, and n squares in the other, for any integer values of m and n. A specific type of hippogonal move can be written ', usually with the smaller number first. A piece making such moves is referred to as a hippogonal mover or leaper. For example, the knight moves two squares in one orthogonal direction and one in the other, it is a hippogonal mover or leaper.
For a ' leaper the occupation of others than the destination square plays no role, thus a leaper moves to the second square diagonally and may thereby leap over a piece on the first square of the diagonal. A leaper can, by the usual convention, move in all directions symmetric to each other, thus e. g. a leaper can move in the four directions,, and.
Other hippogonally moving pieces include the camel, a fairy chess piece, which moves three squares in one direction and one in the other, and thus is a hippogonal mover. The Xiangqi horse is a hippogonal stepper and the nightrider is a hippogonal rider.
The pieces are colourbound if the sum of m and n is even, and change colour with every move otherwise.