Friendly fire adds to the tactical nature of the combat. However it would be nice if there was a way to see the area of effect of a spell before you cast it, while hovering over the ground. Maybe they plan to add this but isn't in the game yet. It's a feature that makes the combat more tactical and less random. If the area of effect is random for some spells then it could be represented for example with 2 circles with the same center, representing the minimun and maximun possible range. Such elements of chance aren't necessarily bad but good turn based combat needs to give good feedback.