Scrabble of points for each lettered tile is based on the letter's frequency in standard English; commonly used letters such as vowels are worth one point, while less common letters score higher, with Q and Z each worth 10 points. The game also has two blank tiles that are unmarked and carry no point value. The blank tiles can be used as substitutes for any letter; once laid on the board, however, the choice is fixed. Other language sets use different letter set distributions with different point values. Tiles are usually made of wood or plastic and are square and thick,
National Scrabble Association on July 1, 2013. Activities of the association included: National Scrabble Association The National Scrabble Association (NSA) was created in 1978 by Selchow & Righter, then the makers of Scrabble, to promote their game. It coordinated local clubs and Scrabble tournaments in North America, including the National Scrabble Championship, until 2009. The last director was John D. Williams, who is co-author of the book "Everything Scrabble". In July 2009, the coordination of tournaments and competitive clubs was transferred to a new organization, North American Scrabble Players Association (NASPA). The NSA continued to publish "Scrabble News" and run programs such as