Sims 3:Creating a game compatible Visual Studio project

New Project

• Set the framework version to .NET Framework 2.0.
• Use the Class Library template.
• Preferably prefix the name of the library with your name / handle. Eg, Gibbed.Sims3Game.Test is what I would use. —Rick

Remove all existing references

• Remove all references on the new project, this is usually System, System.Data, and System.Xml.

Set the project to not reference mscorlib.dll

• Open the project properties.
• Change to the Build tab.
• Set the active configuraiton to All Configurations.
• Click Advanced to open the Advanced Build Settings window.
• Check Do not reference mscorlib.dll and click OK.

Add references to the Sims 3 assemblies

You will need to have already extracted and decrypted the Sims 3 assemblies to do this step.

• Right-click the References item in the Solution Explorer.
• Select Add Reference....
• Select the Browse tab.
• Select all of the Sims 3 assemblies except TestGameplay and TestObjects. The assemblies you want to add are Automation, mscorlib, ScriptCore, SimIFace, Sims3GameplayObjects, Sims3GameplaySystems, Sims3Metadata, System, System.Xml, and UI.
• Click OK.

Fin

You're now ready for coding. :)