Specifically the "Fire Bolt" of the Fire Domain, but applicable to many other Domain special abilities...
Does the use of this (SP) domain ability cause attacks of opportunity? Do they ever require Concentration checks? If so, then what is the DC formulae? Do targets get to save vs. this spell-like attack? If so, what is the DC formulae? There is no "spell of the same name" that I could find in the Core Rulebook, so I seek guidance here.
Thanks in advance!
It's a ranged attack and therefore provokes regardless of anything else, however as a (SP) ability it provokes for that too. If there isn't a save throw mentioned then there isn't a save throw. You can make a Concentration check to not provoke for the spell like ability part (you'll still provoke for the ranged attack though) and the DC should probably be 15+2 = 17 in my opinion. This would be the DC for a concentration check for a first level spell which Fire Bolt mimics (Produce flame is the one I'm thinking of currently).
I Hate to say this, but I have literally been searching for a simple answer like this for about a week now. Major props and Kudos to Abraham for making is simple.
The information is throw here and there on forums and hard to find, but in general to determine a class spell-like ability spell level you have to check what is the highest level of spells available to that class on class level at which the spell-like ability is normally gained. Thus 1st level spell-like ability granted by domain or wizard school is a 1st level spell equivalent (because 1st level cleric/wizard casts 1st level spells), 6th level spell-like ability granted by domain or wizard school is 3rd spell level equivalent, and 8th level spell-like ability granted by domain or wizard school is 4th spell level equivalent.