chess variant

The Chess Players by Lucas van Leyden (c. 1520) depicts a game of Courier chess, a popular medieval chess variant played on a 8x12 board that was played for over 600 years. Magnus Carlsen playing in the 2019 FIDE World Fischer Random Chess Championship. FR, also known as Chess960, is one of the most popular modern Chess variants.

A chess variant is any board game related to, derived from, or inspired by orthodox chess. Chess variants can differ from standard chess in many different ways, including variant board sizes, non-standard fairy pieces, alternative starting positions, and additional rules. There are thousands of known chess variants (see list of chess variants). The Classified Encyclopedia of Chess Variants catalogues around two thousand, with the preface noting that—since creating a chess variant is relatively easy—many were considered insufficiently notable for inclusion. While most chess variants are not widely played, some have reached modest levels of popularity, with the most successful being Chess960. Several well known modern chess masters like Capablanca, Fischer, and Yasser Seirewan developed their own chess variants.