This spell may be cast on arrows, crossbow bolts, or other missiles or thrown weapons. When the missile is fired or thrown, it bursts into flames in mid-flight, causing 1 additional point of damage when it hits, and ignites any flammable object it strikes. The missiles do not count as magical weapons. The caster can only enchant one missile per level in any one round. The spell will not work on ammunition for gunpowder weapons, bombs, or incendiaries.