All of the following are base racial abilities for the tiefling.

Ability Score Adjustments: +2 Dexterity, +2 Intelligence

Outsider Type: Tieflings are native outsiders, so they are vulnerable to spells and effects that work on creatures of the outsider type but immune to effects that target other types. For example, a tiefling would be subject to the extra damage from an outsider bane sword but immune to hold person, since that spell affects only humanoids.

Size: Tieflings are Medium size.

Speed: Tiefling base land speed is 30 feet.

Darkvision (Ex): A tiefling has darkvision to a 60-foot range.

Skill Bonuses: A tiefling has a +2 racial bonus on Stealth and Deception checks.

Automatic Languages: Common, Infernal. Bonus Languages: Draconic, Dwarven, Elven, Gnome, Goblin, Halfling, Orc.

The Tiefling Racial Class

Tiefling Racial Class Features

All of the following are class features of the tiefling racial class.

Darkness (Sp): At 1st level, the tiefling may use darkness (caster level equals tiefling's character level) once per day plus 1 every 3HD. At 20HD at will. 

Energy Resistances (Ex):  Receive energy resistance 5 to fire, cold and electricity.  At 10HD the Tiefling may gain one additional resistance increases by +5, at 15HD gain an additional increase in one resistance by +5, and at 20HD gain a final increase in one resistance by +5