Game mechanics in two distinct ways: Examples of tile mechanics include: "Scrabble", in which tiles are letters and players lay them down to form words and score points; and "Tikal", in which players lay tiles representing newly explored areas of jungle, through which archaeologists (represented by tokens) must move to score game points. Worker placement is a game mechanism where players allocate a limited number of tokens ("workers") to multiple stations that provide various defined actions. The worker placement mechanism originates with board games. Stewart Woods identifies "Keydom" (1998; later remade and updated as "Aladdin's Dragons") as the first game to implement
Challenge (Scrabble) has not seen a single drawn tile yet, in order to consider whether to challenge. To do this, the player simply announces, "Hold," which prevents the opponent from drawing replenishment tiles for 15 seconds (but may draw thereafter, keeping those tiles separate). The player may decide to rescind the hold, or challenge the play. 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