described whenever possible, but these names sometimes differ between circles associated with chess problems and circles associated with chess variants. Classification Many of the simplest fairy chess pieces do not appear in the orthodox game, but they usually fall into one of three classes. There are also compound pieces that combine the movement powers of two or more different pieces. Simple pieces Leapers A leaper is a piece that moves directly to a square a fixed distance away. A leaper captures by occupying the square on which an enemy piece sits. The leaper's move cannot be blocked (unlike elephant and horse in Xiangqi and Janggi) – it "leaps" over any intervening pieces – so the check of a leaper cannot be parried by interposing. Leapers are not able to create pins, but are effective forking pieces. A leaper's move that is not orthogonal (i.e. horizontal or vertical) nor diagonal is said to be hippogonal. Moves by a leaper may be described using the distance to their landing square – the number of squares orthogonally in one direction and the number of squares orthogonally at right angles. For instance, the orthodox knight is described as a (1,2)-leaper or a (2,1)-leaper. The table to the right shows common (but by no means standard) names for the leapers reaching up to 4 squares, together with the letter used to represent them in Betza notation, a common notation for describing fairy pieces. Although moves to adjacent squares are not strictly "leaps" by the normal use of the word, they are included for generality. Leapers that move only to adjacent squares are sometimes called step movers in the context of shogi variants. In shatranj, a Persian forerunner to chess, the predecessors of the bishop and queen were leapers: the alfil is a (2,2)-leaper (moving two squares diagonally in any direction), and the ferz a (1,1)-leaper (moving one square diagonally in any direction). The wazir is a (0,1)-leaper (an "orthogonal" one-square leaper). The dabbaba is a (0,2)-leaper. The 'level-3' leapers are the threeleaper (0,3), camel (1,3), zebra (2,3), and tripper (3,3). The giraffe, stag, and antelope are level-4 leapers (1,4), (2,4), and (3,4). Many of these basic leapers appear in Tamerlane chess. Riders A rider, or ranging piece, is a piece that moves an unlimited distance in one direction, provided there are no pieces in the way. Each basic rider corresponds to a basic leaper, and