[1] It is based on the Official Scrabble Players Dictionary (OSPD) with modifications to make it more suitable for tournament play.
The first edition of OWL was created by the NSA Dictionary Committee, chaired by John Chew, and took effect on March 2, 1998.
To avoid controversy, it was available for sale only to NSA members, and unlike the OSPD, did not include definitions.
To provide additional value for tournament players, the OWL includes words whose base or inflected forms have up to nine letters, rather than the OSPD's eight.
The 2020 update NWL2020[f] differed from its predecessor only in the removal of 259 words deemed to be personally applicable offensive slurs, precipitated by rule changes proposed by the North American holder of SCRABBLE trademarks, Hasbro, Inc., in the wake of that year's anti-racism protests.