In this classic word game, players use their seven drawn letter-tiles to form words on the gameboard. Each word laid out earns points based on the commonality of the letters used, with certain board spaces giving bonuses. But a word can only be played if it uses at least one already-played tile or adds to an already-played word. this leads to slightly tactical play, as potential words are rejected because they would give an opponent too much access to the better bonus spaces.
Description from Boardgamegeek.com