Does the Arcanist Flame Arc exploit trigger attacks of opportunity?
Here is my gaming group's thought process, to show that we did some research, albeit ultimately came up to nothing and I had to rule on the fly so as to not stop the game for more than the 15 minutes we already spent on the issue. We know that general trumps specifics, so we went:
- Take a read at the Flame Arc exploit
The arcanist can unleash an arc of flame by expending 1 point from her arcane reservoir. This creates a 30-foot line of flame that deals 1d6 points of fire damage + the arcanist’s Charisma modifier, plus an additional 1d6 points of fire damage for every 2 levels beyond 1st (to a maximum of 10d6 at 19th level) to each target in the line. Creatures in the area of effect may attempt a Reflex saving throw to halve the damage.
- Look at the Arcanist Exploit feature
By bending and sometimes even breaking the rules of magic, the arcanist learns to exploit gaps and exceptions in the laws of magic. Some of these exploits allow her to break down various forms of magic, adding their essence to her arcane reservoir. At 1st level and every 2 levels thereafter, the arcanist learns a new arcane exploit selected from the following list. An arcanist exploit cannot be selected more than once. Once an arcanist exploit has been selected, it cannot be changed. Most arcanist exploits require the arcanist to expend points from her arcane reservoir to function. Unless otherwise noted, the saving throw DC for an arcanist exploit is equal to 10 + 1/2 the arcanist’s level + the arcanist’s Charisma modifier.
- The exploit is listed as Supernatural, what does it say there, then?
Supernatural abilities are magical but not spell-like. Supernatural abilities are not subject to spell resistance and do not function in areas where magic is suppressed or negated (such as an antimagic field). A supernatural ability’s effect cannot be dispelled and is not subject to counterspells.
There we went on a grinding halt. I ruled that the player could use it without triggering AoO, but since it acts like a lightning bolt, in my head, I believe it should trigger an attack of opportunity, so I warned him I'd look it up and might change it by the next game and he was quite alright with that decision.
As you have guessed, I am the DM, but also our group's Rule Lawyer and if it says clearly somewhere if the ability triggers or not, I would much appreciate to be pointed in that direction to have a good read.