Mechanics

We will be using GURPS for mechanics, as that's what the Discworld book is written in. You can download GURPS Lite [PDF] for free from Steve Jackson Games. Special Discworld things such as spells, etc are in the GURPS Discworld book which is availble for borrow.

When the book returns to me I will try to put up some of the specific setting details. Here is one point (also linked in several other places) on wizardry: How to Cast a Spell by Michael Cule, also found in the Pyramid Burfie campaign.