Sam Lloyd was the America's greatest puzzle creator. One of his games was the "fifteen game", named so because of the fifteen little numbered tiles. You can read here the funny story of this mind game. Everybody knows this logical game's purpose: the player has to order the tiles. Not as many people know that this brain game has interesting mathematical implications. Our version is flexible so you can choose the field's size. You can move the tiles by clicking them. If you use Internet Explorer you can use the arrow keys too to slide the tiles.
