Hi, I've checked some older threads on this topic but couldn't really find a definite answer. Most of those threads are like 4 years old, so I thought I'd ask anew, in case there's been new information I didn't find.
So, long story short: Can a rogue with the scout archetype use Spring Attack and Skirmisher to get guaranteed sneak attack (barring missing with the attack, immunity and so on, of course)?
No. Using Spring attack is a full round action that has no provision for charging.
Yup. I'm actually playing with a similar build right now. Totally works. It's a good combination.
Edit: Milo, he is talking about the 8th level skirmisher ability, not the 4th level scout's charge ability.
No. Using Spring attack is a full round action that has no provision for charging.
You're thinking of "Scout's Charge," not "Skirmisher."
Skirmisher (Ex)
At 8th level, whenever a scout moves more than 10 feet in a round and makes an attack action, the attack deals sneak attack damage as if the target was flat-footed. If the scout makes more than one attack this turn, this ability only applies to the first attack. Foes with uncanny dodge are immune to this ability. This ability replaces improved uncanny dodge.
I see no reason why Skirmisher wouldn't work with Spring Attack as long as you move the 10+ feet before the attack.
The reason it was discuessed when it was released is the ruling that you can't use Vital Strike with Spring Attack because Vital Strike requires "the attack action", which is per definition a standard attack and thus not usable during Spring Attack (a specific full-round action).
Skirmisher calls for "an attack action". It would be different if it would just say "an attack" without the "action" but it's there. So the question remains if that's specifically the attack standard action or just any attack action.
Adding to the confusion is the FAQ regarding Vital Strike + Spring attack not working together. The FAQ has the sentence "Vital Strike can only be used as part of an attack action, which is a specific kind of standard action." [emphasis mine]
So the question is, is "an attack action" automatically the standard action called "attack" or not?
FAQ's only apply to what they are talking about and nothing more. That is a paraphrase directly from the developers.