Fiendish Template

Fiendish creatures dwell in the higher planes, but can be summoned using spells such as summon monster and planar ally.

Modifications

Challenge Rating: A fiendish creature’s CR increases by +1 only if the base creature has 5 or more HD.
Senses: The creature gains Darkvision 60 ft.

Defensive Abilities: The creature gains Damage Reduction, Cold Resistance, and Fire Resistance as noted on Table: Fiendish Creature Defense, as well as Spell Resistance equal to it's new CR + 5.
Special Attacks: Celestial creatures gain Smite Good, as described below.

• Smite Good (Su): Once per day, the fiendish creature may smite a good-aligned creature. As a Swift Action, the creature chooses one target within sight to smite. If this target is good, the creature adds its Charisma bonus (if any) to attack rolls and gains a damage bonus equal to its HD against that foe. This effect persists until the target is dead or the creature rests.

Fiendish Creature Defenses

Hit Dice	Damage Reduction	Energy Resistance
1–4	—	5
5–10	5/evil	10
11+	10/evil	15