There are the following types: Physical and mental, simple and complex. Among these four there are the runic, which adds a layer of complication.
The two basic types are the Inclusive and the Exclusive. The First keeps things in, the second keeps them out.
A pentacle works against one level of entity or lower. They are: a non-physical manifestation, a semi-physical manifestation, or a physical manifestation
There’s more to be said on magick in Dangerous Journeys, most especially on pentacles, but I’m bushed and need a break. To add to that I now have a cold. I want to sleep, but when you’re sleeping you can’t be productive.<sigh>