How to target specifically with spells?

[Covenant]

I've had a lot of luck using spells just 'in general' with my mages, but I'm having a serious issue trying to figure out a way for my mage to be able to case a spell specifically at one unit or another.

The problem is that the excellent high-damage single-person spells are all but useless when cast on a single soldier, but very effective when they hit a large unit. I want to be able to target large units or rearguard troops like mages, but I'm not sure how to do that. The spellcasting doesn't give me a target the same way attacking or firing does.

Without some more direction, I may end up wasting a lot of potent spells on targets that do not require that kind of firepower. Can someone tell me how the AI decides to target things, and if there's anything I can do to make my spell accuracy higher?

Or at least high enough to single out large units and rear units?

[Ironhawk]

You can't effect the targetings of spells.

That said, the spell targeting AI isnt too bad. Single unit spells, like soul slay, usually gravitate towards the bigger units. And things like Blade Wind usually go for the big concentration of low-armor units, like archers.

[Taqwus]

Single-unit spells tend to focus on high-hp units.

This is not necessarily a good strategy, mind you; for instance, it can be a waste of time trying to Soul Slay a high-hp high-MR Abomination. But generally it's not too bad. 'Petrify' doesn't really seem to get wasted on militia.

I've noticed a seeming emphasis on Enslave Mind on routing units, too. Interesting.

Targeting individual units with spells "cast at mages" would give certain paths extreme advantages with the defender-fires-first rule -- imagine having all your commanders smacked down with Gifts from Heaven first turn. Not fun.

[Gandalf Parker]

What you want to do is get your mage to the back of the fight so that his field of vision includes more of what you want targeted. Setting them flanking (way off to the sides) then having them hold, attack a round, then cast can sometimes help.

[Graeme Dice]

Mages do not have a field of vision. They can see every unit on the battlefield. They might not be in range to cast a particular spell on every unit on the battlefield, but they certainly can target any unit.