if you want to go this route) and building it from scratch while keeping it balanced with the rest of the Gurps rules.

Now making magic work just right for your setting is still a daunting task but Gurps Thaumatology turns it from nearly impossible to merely challenging.

This book collects and updates all of the alternate magic systems from the previous edition as well as adding a few new things. It's not mind blowing or anything but it's an excellent reference for a campaign that uses magic other than spell based.

Thaumatology packs in virtually any type of magical system that a GM could want. I like it better than GURPS Magic, because several of the systems offer a way to bypass the huge spell lists that I did not want to deal with (virtually the entire use of Magic). Some people will like different magic systems than others, but this book offers so many, every will find something in it to use.

Note:You don't need GURPS Magic to use this book, which is a plus because, as of this writing, Magic is out of print and pricy, though the two books are compatible.