Fairy chess piece

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 unorthodox chess problems, known as fairy chess. 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.[1]

  1. ^ Unicode proposal for heterodox chess pieces Archived 2017-07-24 at the Wayback Machine. Quotes: "Most fairy pieces are conventionally represented by rotating the standard chess piece symbols." (p. 1); "Unlike the standard upright symbols, which always correspond to the orthodox pieces, there is no strict one-to-one correspondence between rotated symbols and particular piece types: the number of fairy pieces in use is uncountable, and the number of possible pieces is infinite. Instead, rotated symbols are assigned to pieces as needed, and the composer has wide latitude in choosing which ones they feel are appropriate, with only a few very common ones fixed by convention..." (p. 2); "The use of distinct symbols for these pieces is more common among players of the aforementioned variants than among problem enthusiasts" (p. 6).