California Code, Civil Code - CIV § 1575

1. In the use, by one in whom a confidence is reposed by another, or who holds a real or apparent authority over him, of such confidence or authority for the purpose of obtaining an unfair advantage over him;

2. In taking an unfair advantage of another's weakness of mind; or,

3. In taking a grossly oppressive and unfair advantage of another's necessities or distress.