Persist in engine or server-side script?

A question I've been wondering about is when it is best to store some information in the engine as opposed to storing it in server-side script. A good example is health. Currently, your health is peristed in the engine code. Theoretically you could persist it in the server-side scripting, as the current inventory system is persisted. One reason to keep certain info in the engine could be for client prediction I'm guessing. In general, though, what are some good guidelines?

Dave Myers
21-6 Productions