A fairy chess piece, variant chess piece, unorthodox chess piece, or heterodox chess piece is a chess piece not used in conventional chess but incorporated into certain chess variants and some chess problems. Compared to conventional pieces, fairy pieces vary mostly in the way they move, but they may also follow special rules for capturing, promotions, etc. Because of the distributed and uncoordinated nature of unorthodox chess development, the same piece can have different names, and different pieces can have the same name in various contexts. Most are symbolised as inverted or rotated icons of the standard pieces in diagrams, and the meanings of these "wildcards" must be defined in each context separately. Pieces invented for use in chess variants rather than problems sometimes instead have special icons designed for them, but with some exceptions (the princess, empress, and occasionally amazon), many of these are not used beyond the individual games for which they were invented. Background The earliest known forms of chess date from the 7th century in Persia (chatrang) and India chaturanga. They had different rules from the modern game. The game was then transmitted to the Arabs, then to the Europeans, and for several centuries, it was played with those ancient rules. For example, the queen was once able to move only a single square diagonally, and the bishop was leaping two squares diagonally. The change of rules occurred in Spain in the end of the 15th century when the queen and the bishop were given the moves they have today. In the old Muslim manuscripts those two pieces were referred as a ferz (meaning advisor) and fil (meaning elephant). The queen is still called ferz in Russian and Ukrainian and the bishop is still called alfil (from al fil, with the article) in Spanish. Due to the piece's change in movement, the ferz and the alfil are now considered non-standard chess pieces. As those who created modern chess in the 15th century, modern chess enthusiasts still often create their own variations of the rules and the way the pieces move. Pieces which move differently from today's standard rules are called "variant" or "fairy" chess pieces. The names of fairy pieces are not standardised, and most do not have standard symbols associated with them. Most are typically represented in diagrams by rotated versions of the icons for normal pieces. This article uses common names for the pieces