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,
English-language Scrabble English-language Scrabble English-language Scrabble is the original version of the popular word-based board game invented in 1938 by US architect Alfred Mosher Butts who based the game on the letter distribution in "The New York Times" in English. The Scrabble variant most popular in English is standard match play, where two players compete over a series of games. Duplicate Scrabble is not popular in English, and High score Scrabble is no longer practised. Although English is a worldwide language, the official list of allowable words and some tournament rules change between territories. The main Scrabble associations in North America are