To earn this achievement start up any Scrabble game (solo, local, or XBL) and play for one hour. This achievement is cumulative, so if you don't get it on your first game (I didn't) you should get it on your second. The achievement unlocks when you finish the game. If you're playing on solo, all you have to do is trade your tiles in three times to end the game, so if you find it running long you cen end it pretty quick.