Acceptable Words

Acceptable words are those words found as primary entries in some chosen dictionary, and all of their inflected forms. Words that are hyphenated, capitalised (such as proper nouns), marked as foreign, or appear only as part of multi-word phrases are not allowed (unless they also appear as acceptable entries: "Japan" is a proper noun, but the verb "japan" - to decorate with black enamel or lacquer - is acceptable). Variant spellings, slang or offensive terms, archaic or obsolete terms, and specialised jargon words are allowed if they meet all other criteria for acceptability. "College" level dictionaries are generally used in preference to unabridged dictionaries.

In formal competition, pre-compiled official word lists are used (usually compiled from combinations of several college dictionaries), along with an official dictionary for backup. The pre-compiled word lists generally contain only words of two to eight letters - those most frequently used in the game. (One letter words are impossible to play, and you only get seven tiles on the rack at one time, so it is very difficult to build a word that is longer than eight letters.) The dictionary is consulted for longer words.

There are two popular competition word lists: the North American 1998 Official Tournament and Club Word List (OTaCWL) or for school use the bowdlerised Official Scrabble Players Dictionary, Third Edition (OSPD3), and the British Official Scrabble Words. North American competitions use the Long List for longer words, while the British use the Chambers Dictionary but may soon change to the Collins Dictionary.

The OWL and the OSPD3 are compiled using seven major dictionaries, including M. Webster 10th Edition. If a word appears in five of the seven dictionaries, it is included in the OWL. The OSPD3 available in bookstores differs from the official competition word list, in that it is marketed for "home and school" use, and has been expurgated of many words judged offensive. These are still legal in competition.

Many international competitions use both the British and American word lists. The union of the two lists is commonly referred to as SOWPODS, derived from an anagram of OSPD+OSW. Many countries in the English Scrabble-playing world now use SOWPODS (published in the UK as Official Scrabble Words International, or OSWI) for their own tournaments year round, with the United States, Canada, Israel, and Thailand being notable exceptions. In 2005, The Fourth Edition of the OSPD was released.