Misfirings from my Neurons

Spell Law usually does not consider the size of a spell target relative to the caster except in the case of Flight spells (see 10.9). I have extended that concept to cover cases when a caster attempts to affect (with spells such as Invis or Silence) targets much larger than his or herself. The 20% weight multiple could be used or for a volume multiplier (perhaps in 100% increments).

This occured when a player wanted to make a flying steed, with a 20 foot wingspan, invisible. A 10'R on himself was insufficient. But the spell, if tried on the steed itself, would require an ESF per 10.9. More as we banter back and forth on this one.