Whenever a ranger chooses a new favored enemy, or increases the bonus to an existing favored enemy, he may choose, in addition to the standard bonuses listed in the PHB, one of the following features, which then affects all attacks against such creatures (or attacks by such creatures, in the case of a defensive bonus):
1. Sneak attack 2d6. This works just as the rogue ability of the same name. If the favored enemy type is naturally immune to sneak attacks (such as oozes or undead), it is still subject to this sneak attack (unless the creature is protected from sneak attacks in some manner as well). This ability may be chosen more than once, and the effects stack. (If a creature falls into two categories of favored enemy, however, the effects from the two categories overlap.)
2. Superior critical. The ranger automatically confirms all critical hits against the favored enemy. If the favored enemy type is naturally immune to critical hits, the ranger may affect them with critical hits anyway (unless the creature is protected from critical hits in some other manner as well).
3. The ranger gets a +4 dodge bonus to AC against attacks by such creatures, and a +4 bonus on all saves against abilities granted by a race of the favored enemy type or a template that changes the creature's race to that type. The save bonus applies regardless of whether the creature is actually of that type; a ranger with Abberration as a favored enemy would get a bonus against the spell-like abilities of a half-dragon aboleth even though it is a dragon rather than an aberration.
This ability may be taken more than once; the effects stack. (If a creature falls into two categories of favored enemy, however, the effects from the two categories overlap.)
4. The ranger's attacks are automatically considered to have a particular property for purposes of bypassing the damage reduction and regeneration of the favored enemy, or of something that gained such a property from being of a race of that type (even if it does not have the type due to a template). The property depends on the selected creature type:
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Construct: Adamantine
Dragon: +2 to magical enhancement bonus (so a nonmagical weapon is considered magical, and a +4 or better weapon is considered epic).
Elemental (Earth): Bludgeoning
Fey: Cold Iron
Giant: Fire or acid (this is randomly selected when the ability is chosen, and may not be changed.)
Magical Beast: +2 to magical enhancement bonus.
Monstrous humanoid: +2 to magical enhancement bonus.
Outsider (Chaotic): Cold Iron. If the ranger is lawful-aligned, the attack is also considered to be lawful-aligned.
Outsider (Evil): Cold Iron or Silver or +2 to magical enhancement bonus (choose one when this ability is taken; it may not be changed. This ability may be taken up to three times to get the others.) If the ranger is good-aligned, the attack is also considered to be good-aligned.
Outsider (Good): +2 to magical enhancement bonus. If the ranger is evil-aligned, the attack is also considered to be evil-aligned.
Outsider (Lawful): Chaotic. This requires the ranger to himself be chaotic.
Outsider (any elemental): +2 to magical enhancement bonus.
Undead: Bludgeoning
Other enemies: This ability may not be taken for such enemies.
If an enemy belongs to more than one favored enemy category, the effects may all be applied, but increases to effective magical enhancement bonus do not stack.
5. A +10 bonus to all knowledge checks regarding creatures of the favored enemy type. A knowledge check to which this ability applies is always considered trained. This may only be taken once for each favored enemy, and the effects overlap for a creature falling into more than one favored enemy category.