In the following, short tutorial you can learn how to invite the whole neighbourhood! In the Neighbourhoodscreen, open up the cheat window and enter the cheat: boolprop TestingCheatsEnabled true Enter your desired lot and Shift click the Mailbox. Choose Invite all Neighbors and instantly, dozens of Sims will enter the lot. As you can see in the right picture, it can become pretty crowded. When you're done, disable the cheat with boolprop TestingCheatsEnabled false. I'm not sure if there is a limit to the amount of Sims that come to the house, but better not try this in a Neighbourhood with for example 400 Sims in them. Too many Sims on screen will slow it down enormously and may even crash your game. That said, it's great for parties without having that annoying timer where everyone leaves when it runs out. With this cheat, they stay until it's late or when they start to get hungry.