Sneak Attack

While Obsidian has not confirmed the existence of sneak attack in NWN2, it is a class feature of the rogue, arcane trickster, assassin and blackguard class which have been confirmed.

3.5 Sneak attack
If a class with this feature can catch an opponent when he is unable to defend himself effectively from her attack, she can strike a vital spot for extra damage.

The character’s attack deals extra damage any time her target would be denied a dexterity bonus to AC (whether the target actually has a dexterity bonus or not), or when the rogue flanks her target. This extra damage is not increased by critical hit damage multiplier.

If a character gets sneak attack from multiple sources the bonuses to damage stack.

Nonlethal damage
With a sap (blackjack) or an unarmed strike, a rogue can make a sneak attack that deals nonlethal damage instead of lethal damage. She cannot use a weapon that deals lethal damage to deal nonlethal damage in a sneak attack, not even with the usual –4 penalty.

Ranged restrictions
Ranged attacks can count as sneak attacks only if the target is within 30 feet.

Target restrictions
A character can sneak attack only living creatures with discernible anatomies. Any creature that is immune to critical hits is not vulnerable to sneak attacks.

e.g. Undead, constructs, oozes, plants, and incorporeal creatures lack vital areas to attack.

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. A rogue cannot sneak attack while striking a creature with concealment or striking the limbs of a creature whose vitals are beyond reach.

Pre-release notes

 * NWN did not incorporate non-lethal damage. NWN2 may not include it either for the same reasons.

NWN comparison

 * Assassins in NWN don't directly gain sneak attack bonus. Instead, the additional damage is incoporated into a altered version of the death attack ability.

External resources

 * NWNWiki:Sneak Attack
 * NWNWiki:Death Attack