In Heroes IV there are two interesting spells. Fortune is of level 2, costs 3 mana, and gives a recipient 100% chance to halve any incoming damage. That's powerful -- essentially a universal Ward spell!
Summon Leprechaun, at the same time, is a 1st-level spell, costing 2 mana. It summons a stack of 0.33*Level*Meditation Leprechauns. They can cast the same Fortune spell at the same turn, and cast it again if you summon more Leprechauns in the stack. After that they may possibly soak a retaliation or two, while your real strikers deal damage. So, that's available for a weaker Druid, costs less mana, and provideds us with a bonus creature stack.
Is there any reason to cast Fortune if Summon Leprechaun spell is also available?