SOWPODS is the word list used in tournament Scrabble

Scrabble

Scrabble is a word game in which two to four players score points by forming words from individual lettered tiles on a game board marked with a 15-by-15 grid. The words are formed across and down in crossword fashion and must appear in a standard dictionary. Official reference works provide a list...

 in most countries except the USA, Thailand and Canada. The term SOWPODS is derived from the anagram

Anagram

An anagram is a type of word play, the result of rearranging the letters of a word or phrase to produce a new word or phrase, using all the original letters exactly once; e.g., orchestra = carthorse, A decimal point = I'm a dot in place, Tom Marvolo Riddle = I am Lord Voldemort. Someone who...

 of the two acronyms OSPD

Official Scrabble Players Dictionary

The Official Scrabble Players Dictionary or OSPD is a dictionary developed for use in the game Scrabble, by speakers of American and Canadian English.-Creation:...

and OSW

Chambers Dictionary

The Chambers Dictionary was first published by W. and R. Chambers as Chambers's English Dictionary in 1872. It was an expanded version of Chambers's Etymological Dictionary of 1867, compiled by James Donald...

, these being the original two official dictionaries used in various parts of the world at the time. Although the two source dictionaries have now changed their respective titles the term SOWPODS is still used by tournament players to refer to the combination of the two sources. There has not been any actual hard-copy list produced called SOWPODS, although the current Collins Scrabble Words, or CSW, is in effect the full SOWPODS list by a different name.

Currently the two main sources for the words making up the combined list known as SOWPODS are:

• The British words. Derived from two sources; the Collins English Dictionary
  Collins English Dictionary
  The Collins English Dictionary is an important printed dictionary of English. It is published by HarperCollins.The first edition of the Collins English Dictionary with Patrick Hanks as editor and Lawrence Urdang as editorial director, was a milestone in British dictionary making as it was the...
  
  and the Collins Corpus, and
• The American words. From the Official Tournament and Club Word List, or TWL
  Official Tournament and Club Word List
  Official Tournament and Club Word List or Tournament Word List, referred to as OTaCWL, OWL, or TWL, is the official word authority for tournament Scrabble in...
  
  , published in 2006 derived from the Merriam-Webster's Dictionary and four other collegiate dictionaries.

History

In 1980 in the United Kingdom, the Chambers Dictionary

Chambers Dictionary

The Chambers Dictionary was first published by W. and R. Chambers as Chambers's English Dictionary in 1872. It was an expanded version of Chambers's Etymological Dictionary of 1867, compiled by James Donald...

replaced the Shorter Oxford Dictionary

Oxford English Dictionary

The Oxford English Dictionary , published by the Oxford University Press, is the self-styled premier dictionary of the English language. Two fully bound print editions of the OED have been published under its current name, in 1928 and 1989. The first edition was published in twelve volumes , and...

 as the official choice for arbitration of the British National Scrabble Championship. In 1988 for the first time a single list of all the valid words, without the ambiguity of discussing conjugations

Grammatical conjugation

In linguistics, conjugation is the creation of derived forms of a verb from its principal parts by inflection . Conjugation may be affected by person, number, gender, tense, aspect, mood, voice, or other grammatical categories...

, declension

Declension

In linguistics, declension is the inflection of nouns, pronouns, adjectives, and articles to indicate number , case , and gender...

s and plural

Plural

In linguistics, plurality or [a] plural is a concept of quantity representing a value of more-than-one. Typically applied to nouns, a plural word or marker is used to distinguish a value other than the default quantity of a noun, which is typically one...

s was published under the title Official Scrabble Words from Chambers (this would come to be known as OSW). North American Scrabble was using the OSPD, hence when the first World Scrabble Championship

World Scrabble Championship

The World Scrabble Championship is the most prestigious title in competitive English-language Scrabble. It has been held every second year since 1991. The current World Scrabble Champion is Nigel Richards...

took place in 1991 words from either word source were allowed.

Over the following years there was disagreement in the competitive Scrabble community over the desirability of a combined word source, which came to be known as SOWPODS as an easily-pronounced anagram of OSW and OSPD. Australia changed all its rated tournaments to using the SOWPODS word list in 1994, while the UK made the same change in 2001. This latter move coincided with the publication of the first official book to contain all words from OSW and OSPD (Chambers' Official Scrabble Words: International Edition).

Word count

The current combined SOWPODS list contains 267,751 words, of which there are:

Number of letters	2	3	4	5	6	7	8	9	10	11	12	13	14	15
Number of words	124	1,292	5,454	12,478	22,157	32,909	40,161	40,727	35,529	27,893	20,297	13,857	9,116	5,757