When Are Pattern Spheres Required?

Normally when you cast an effect your Mage is changing something specific about the universe. Sometimes, however, he wants the effect to be independent of himself. When this happens you need to use a pattern sphere.

For example, let's pretend you and a friend are robbing a bank. You use a rote to make the security guard ignore your friend while he robs the bank. This is Mind 2- you are simply casting a rote on the security guard to make him ignore something.

What if, however, your friend wants to rob the bank during the day? You have two options. You can use Correspondence 2 to affect everyone in that location simultaneously OR you can enchant your friend, which requires Life 2.

What happens is this: instead of using a rote to make the security guard ignore them you are using a rote to alter your friend so that they are ignored. The effect becomes independent of the mage, who merely maintains it. To alter your friend so they act on other patterns requires Life 2 to attach the effect to them. You are not interacting with the targets ( the people who are ignoring your friend), your friend's pattern is. That requires to the effect to be on your friend themselves and that requires the pattern sphere.