The trick is in our character creation process. We create our characters where they have backgrounds. When you read your characters sheet you will know who you know in the game, why you know them & what schemes you may have going on. Everything ties in together. The you will get a second sheet that tells you what secrets you have that you don't want others to know. (There may be other characters that know your secrets and choose to use that knowledge as leverage in whatever way they choose to). Then you get a list of secrets you know about other people. (Again you can use this info in so many interesting ways). You will know why you know these secrets too. It is all intwined with your background. Then lastly you will get a list of things you need to do. You do these in the way you want to. These actions are written for a reason. Mostly to create more conflict in the game

With this information your guests can play their character in any way they want. You will find out how sneaky and imaginative your guests really are. Some people worry that there guests will have no imagination and that the party will flop. This will not happen. I have hosted MANY of these parties & not one party has ever flopped & not one guest had no imagination, no matter how shy they are. I think human instinct takes over once they get past the nervousness of doing something new. Here is an example:
If someone comes up to you and tries to blackmail you for something it is up to you to decide how you want to handle it. Do you give in? Do you hire someone to take them out or do it yourself? Do you dig up dirt on them to get them to back down? Do you threaten them? Each person will decide this on their own and whatever choice they make will create more drama. Who knows where their decision is going to lead them. What new conflicts, what new schemes?
Characters will form partnerships. 2 characters who seem to not be very acquantined may be secretly plotting your downfall! Your guests are only limited by their imagination and if you worry that they may not have any, you will be very surprised by what they come up with.
Hope this helps and if anyone has played our games I would appreciate their feedback here so others can learn first hand about the pleasurable experience of playing an unscripted game.