Battle magic
Casters roll two dice plus their Magic Skill against a spell's Casting Value. Land it and a Searing Bolt, Fireball, Terror or Force Push goes off. A caster keeps every spell he knows all battle — the cost isn't ammunition, it's the roll. Fail and nothing happens; roll badly enough and the magic turns on its own caster.
Open ground
Woods · cover
Hills · cover
Village · open
High ground · +1 firing down
River · impassable
Bridge · the crossing
Tower · +1 die