SIMS3PACK - The Sims 3 Package File is a neat game package and file that you can use specially for Sims 3. Players, in this game, are able to manipulate an environment which is simulated with many different people that are virtual. If you are looking for a file extension, this is definitely the one you should go with because it really makes a big difference. There are many different features you can get out of this file extension for your Sims game. The pack is directly imported right into the game, so you will have everything right at your fingertips. All of your content that has been imported will be available the next time that you turn your game on.