In order to play a game of SCRABBLE®, players must agree to a dictionary in order to adjudicate any challenges that may occur. How do you know if a word is really a word? It depends on your lexicon!
Official SCRABBLE® Players Dictionary (OSPD)
The Official SCRABBLE® Players Dictionary is for household play. Published by Merriam-Webster, this lexicon is considered family-friendly as many words deemed offensive have been omitted. It is currently in its fifth edition and is sold in most major bookstores. Words printed in this dictionary go up to eight letters in length.
Official Tournament and Club Word List (OWL/TWL)
The Official Tournament and Club Word List is the primary lexicon used in Canada, the United States and Thailand. This is one of the lexica used at the Mississauga SCRABBLE® Club. It is based on OSPD, but contains more words than OSPD because it includes offensive words, some trademarked terms (e.g. “KLEENEX”) and words longer than eight letters. Last updated in 2014, OWL consists of 187632 words. As it is strictly a list, it typically does not contain definitions.
School SCRABBLE® Word List (OWL/TWL)
The School SCRABBLE® Word List is the primary lexicon used for school play in North America. It is similar to OWL, but does not include words deemed offensive.
Collins SCRABBLE® Words (CSW)
Collins SCRABBLE® Words, also known as Collins and formerly SOWPODS, is the primary official lexicon used in most of the world outside North America. Thus, it is used in major international tournaments such as the World SCRABBLE® Championship. Many tournaments in North America offer Collins divisions in addition to OWL divisions. Last updated in 2015, Collins consists of 267751 words, approximately 80000 more words than OWL. This is one of the lexica used at the Mississauga SCRABBLE® Club.
If you want to review any of these word lists yourself, visit the Apps page and download a dictionary.