Arcane Trickster Abilities in Pathfinder: Wrath of the Righteous covers all the special abilities, be it passive or active, that one of the thirteen Prestige Classes of the game possesses.
Arcane Trickster Features/Abilities
If a character can catch an opponent when he is unable to defend himself from his attack, he can strike a vital spot for extra damage.
The character's attack deals extra damage anyttime his target would be denied a Dexterity bonus to AC (whether the target actually has a Dexterity bonus or not), or when the character Flanks his target. This extra damage is 1d6 and increases by 1d6 at later levels. This additional damage is precision damage and is not multiplied on a critical hit.
The character must be able to see the target well enough to pick out a vital spot and must be able to reach such a spot.
Beginning at 3rd level, an Arcane Trickster can enter a special stance that allows him to improvise a way to sneak attack targets regardless of their awareness. An Arcane Trickster can maintain this stance for one round per day. For every two levels above 3rd, an Arcane Trcickster can maintain this stance for one additional round, up to a maximum of 4 rounds at 9th level. The target of impromptu sneak attacks loses any Dexterity bonus to AC, but only against those attacks. The power can be used against any target, but creatures that are not subject to critical hits take no extra damage (though they still lose any Dexterity bonus to AC against the attack).
At 10th level, an Arcane Trickster can add his sneak attack damage to any Spell that deals damage, if the targets are Flat-footed. This additional damage only applies to Spells that deal hit point damage, and the additional damage is of the same type as the spell. If the spell allows a saving throw to negate or halve the damage, it also negates or halves the sneak attack damage.
At 1st level, Arcane Trickster selects an arcane spellcasting class she belonged to before adding the prestige class. When a new Arcane Trickster level is gained, the character gains new Spells per day and new Spells known as if she had also gained a level in that spellcasting class.
At 9th level, an Arcane Trickster can become invisible, as if under the effects of greater invisibility, as a Free Action. He can remain invisible for a number of rounds per day equal to his Arcane Trickster level. These rounds need not be consecutive.