Is there anyway to tell which spells actually cause Friendly Fire? Or is it trial and error. 

 

For example, Wizard Rolling Flame says it does damage to "anyone in it's path." But actual use show it does not affect friendly targets. 

Spells that say "Foe only AoE" in the description do not cause friendly fire.

Spells that say "Foe only AoE" in the description do not cause friendly fire.

I don't see anything like that for Rolling Flame as an example. 

And I just tested it again. And now Rolling Flame is doing friendly fire...

 

Thanks for the answer. 

Rolling Flame is supposed to do FF. If you experienced otherwise, it's likely a bug/pathing error. I know Rolling Flame has had some (hilarious) pathing errors, especially when interacting with the seams in the world environment.

Kind of ON topic: I would love if voice sets for player made characters and recruitable companions had one line for when they receive damage from friendly fire.

Kind of ON topic: I would love if voice sets for player made characters and recruitable companions had one line for when they receive damage from friendly fire.

 And particularly ornery companions could call out the wizard/priest/other responsible after the battle and maybe do a little knock down or similar action? 

"Anyone in it's path" kinda gives it away!