Monopoly Cheats

There is a bug in the CPU player artificial intelligence that allows you to acquire many properties in exchange for just one of yours by renegotiating their side of the trade. When a computer player offers to trade a property with you, press 8 to switch to their trade window, then choose "Add property". You can then add any of the undeveloped properties they own apart from ones belonging to the same colour group as the property they want from you (so if they want one of the yellow properties off you, for example, you should not add either of the other two yellow properties to the trade list). They will accept the trade every time, even if you're exchanging a single property for several complete sets!