At the very start of the game, each space in the board will have a diamond symbol on it. The first person that lands on each space will be given a Fortune Card. Fortune Cards can be any number of things, including Sly Deal and Forced Deal cards. The Sly Deal card allows the player that uses it to steal any property from another player uncontested (except if that property is already part of a monopoly). The Forced Deal card is similar, but you must give up one of your properties in the forced deal as well. In 4-player pass-and-play, after a few trips around the board, see which (if any) player has both a Forced Deal and a Sly Deal card. Then use both of them in the game. To use the cards, when it is a player's turn, click on their icon in their respective corner of the screen. Then select the card you want to use. This is also how you see which players have which cards. This process can be combined with the "Deal Breaker" achievement.