English-language Scrabble at club level in the UK. Tournaments follow a similar structure to American ones, usually at least 6 games but weekend tournaments where players play 12 to 16 games are not uncommon. The official Scrabble association the Association of British Scrabble players sanctions official tournaments with official ratings, ratings range from about 200 to about 60. The official dictionary is called SOWPODS. In contrast to American tournaments, players do not lose a move if they challenge a valid word, which in general means more words are challenged. There are only Scrabble competitions for primary and secondary school students in Hong
Word square place names). However, 11-squares are possible if words from a number of languages are allowed ("Word Ways", August 2004 and May 2005). It is possible to estimate the degree of difficulty of constructing word squares. 5-squares can be constructed with as little as a 250-word vocabulary. Roughly, for each step upwards, one needs four times the number of words. For a 9-square, one needs over 60,000 9-letter words, which is practically all of those in single very large dictionaries. For large squares, the vocabulary prevents selecting more "desirable" words (i.e. words that are unhyphenated, in common use, without contrived inflections,