One thing I think that makes combat in this game a little bland is that normal units don't have special abilities. In Master of Magic, most units had a special ability of some type. I think that this should be added to Elemental to give it some more tactical complexity. Here are some examples:
- Large Shield - In addition to normal defense, gives extra defense against ranged attacks.
- Throwing Axe/Throwing Dagger - Unit gets a +2 to their first attack in any combat.
- Pike/Halbard - Gives a bonus against cavalry, and gives a first-strike ability (i.e. response attack happens before initial attack)
- Wizard's Robe - Full armor set that lets the unit shoot magic bolts.
- Holy Symbol - Allows a unit to cast a Heal spell.
- Medal of Honor - Gives bonus to morale.
More creative people could probably come up with some more ideas.
