http://lemuria.org/SM3/welcome/skillsParagraph 2: (Emphasis is mine.)
There is a hard limit determined by the skill level in that no magician can create an effect with a power level beyond the sum of his levels in the skills required.
There is an implicit limitation as well, in that you must have at least one skill level in both the Base and the Intent. I suggested this be clarified on the web site, but Tom did not comment on it.
