Any game designer will tell you that coming up with rules for magic is one of the toughest parts of the process. And making those rules fit the mold established by an existing work is even tougher.
One part of the rules I've never been fully happy with is Transmutation, the magical practice of transforming objects. In the book, I use a 1-5 scale to estimate the severity of change with few real guidelines. But I haven't had anything better to go on. Until now.
My current idea rates a transmutation on four points: Form, Function, Size, and Substance. Whenever a transmutation would change one of those things, the Power of the spell goes up by 1. If a category is severely altered, the Power can go up by 2. Let's run a few examples to illustrate.
Hanky Camp: This spell will transform 3 handkerchiefs into tents to allow a group of travelers to camp comfortably. From hanky to tent is a definite change to Form (1) and Function (1), as well as a severe change to Size (2). Substance is still very much the same, as both hankies and tents are made of fabric. Power 4
Mrs. Yoop's Breakfast: To start her day, Mrs. Yoop transmutes a pot of water into coffee. Form, Function, and Size are not significantly affected by the change. The main factor to change is Substance, making this only a Power 1 effect. Her “Rocks into Fishballs” spell is similarly a simple change in Substance, with the other factors staying significantly the same.
Try this rule out and let me know how it works for you.
Also, keep those contributions coming on the Kickstarter. According to that little widget over on the right, I'm only 3% funded and I have only 27 days to get the rest. And remember, according to the Kickstarter rules, if I don't get everything, I get nothing.