Type: General
Source: Complete Mage
Through study, you have learned how best to defend yourself against your favored enemies' spells and how to best affect them with your own.
Prerequisite: Knowledge 6 ranks (in appropriate skill; see below) or favored enemy class feature.
Benefit: Choose a creature type for which you have the favored enemy class feature, or one associated with a Knowledge skill in which you have at least 6 ranks (see below). If you choose humanoid or outsider, you must also choose a subtype from Table 3-14: Ranger Favored Enemies (PH 47).
You gain a +1 bonus on caster level checks to overcome the spell resistance of the chosen creature type, and such creatures take a -1 penalty on saves against your spells and spell-like abilities.
| Creature Type | Associated Knowledge Skill |
| Aberration | Dungeoneering |
| Animal | Nature |
| Construct | Arcana |
| Dragon | Arcana |
| Elemental | The planes |
| Fey | Nature |
| Giant | Nature |
| Humanoid (any) | Local |
| Magical beast | Arcana |
| Monstrous humanoid | Nature |
| Ooze | Dungeoneering |
| Outsider (any) | The planes |
| Plant | Nature |
| Undead | Religion |
| Vermin | Nature |
Special: You can take this feat multiple times. Each time you take this feat, you choose a new creature type (or subtype, in the case of humanoids or outsiders).