I'm setting up a magical effect that will change the size of the user. More specifically, it will shrink the user to the size of a mouse. Looking at the MuCo guidelines, changing size has a Base of 3. But does this take into account how big a change the effect will have? Should I use the same Base level for a change in one size and a change in 10 sizes?
I've been wondering about this too. The Preternatural Growth and Shrinking spell gives what looks like an arbitrary +1 "because the spell allows growth of two types of shrinking." So if your spell is intended to shrink the target by a very large degree, but to only one size, is no magnitude increase warranted? A knotty problem.
It came up because we recently faced an antagonist who was magically cultivating bee products (I'm not sure if this was a published scenario or not, so some of you might be familiar with it). My sodalis and I became completely fascinated by all the bee-related stuff and determined to A) establish bee colonies in our covenant, and B) devise a means of shrinking ourselves to bee size so as to allow us to observe the process by which the bees choose their king bee. Eventually, I hope to execute C) awaken human-level intelligence in a particular bee colony, to observe the distinctions between the base nature of bees and that of humans that allow bees to cooperate so efficiently.