 Scrabble and Scrabble-like game sites on the Internet such as Yahoo!Games' Literati, Internet Scrabble Club and Lexulous offer automatic verification as an option, which makes it impossible to play an invalid word.The Facebook version of Scrabble and Zynga's mobile game Words With Friends make automatic verification compulsory without imposing a penalty for wrong guesses or a limit on the number of attempts, allowing players to guess repeatedly at words until the computer verifies one to be acceptable.