The third edition of the Official Tournament and Club Word List (OTCWL2014, also known as OWL2014, TWL2014 or in older documents OWL3) went on sale initially at the 2014 National SCRABBLE Championship, is now available at the NASPA Store, and takes effect on December 1, 2014. See the OTCWL2014 page for more details about that book.
The second edition of the word list (OTCWL2, a/k/a OWL2, TWL2) is (until November 30, 2014) the official word list for NASPA-sanctioned club and tournament play, and contains words of up to nine letters and their inflections. (Longer words are listed in Long List.) OTCWL2 is edited by the Dictionary Committee (whose wiki page goes into the lexicon’s history in greater detail), published by and exclusively available to NASPA members from Merriam-Webster.
The tournament word list is not available to the public in electronic form; it was available in print from Merriam-Webster. The electronic word list is available to authorized SCRABBLE developers. If you are not sure if you have the correct version of the digital file, here are some statistics you can check. There are currently 101 2-letter words, 1015 3, 4030 4, 8938 5, 15788 6, 24029 7, 29766 8, 29150 9, 22326 10, 16165 11, 11417 12, 7750 13, 5059 14 and 3157 15, for a total of 178,691 words. (13 of those words are not playable using the standard 100 tiles: CLASSLESSNESSES, KNICKKNACK(S), PIZZAZZ(ES), PIZZAZZY, POSSESSEDNESSES, RAZZAMATAZZ(ES), RAZZMATAZZ(ES), SENSELESSNESSES, STRESSLESSNESS.) The master file lists all words in lower case in alphabetical order, one per line, with each line terminated by a Unix line break. It is 1763167 bytes long and has BSD checksum ('cksum -o 1') 12722, System V checkum ('cksum -o 2') 24638, 32-bit CRC ('cksum -o 3') 2022312244, ISO/IEC 8802-3:1989 checksum ('cksum') 427611949 and MD5 checksum dfd408f47cc1a324eb0ab5577910e4e3.
See also our main FAQ page.
Incorrectly omitted from OTCWL2: CRABAPPLE (p. 98), CRABAPPLES (p. 98), DEVELOPPES (p. 118), GODDAMNDEST (p. 186), MUNCHABLES (p. 279) and VIREONINES (p.485).
Incorrectly included in OTCWL2: CRABABBLE (p. 98), CRABABBLES (p. 98), GODAMNDEST (p. 186) and WEAPONEERED (p. 491).
The word ANTEFIXAE was incorrectly omitted from the printed edition of OTCWL1.