If your ranger chooses humanoids or outsiders as a favored enemy, he ought to also pick an involved subtype, as indicated on the table. If a selected creature falls into more than one class of favored enemy, the ranger's bonuses do not stack; he just uses whichever bonus is greater. https://felixacbay.thezenweb.com/Dungeon-Dragons-Ranger-Fundamentals-Explained-48744295