Ogre-Mage spells:
Eye of Kilrog: This is the fastest thing in the game, but it dies after a while. You use it to spy and scout at other cities.
Runes: This spell rules. Runes are kind of like land mines.
Bloodlust: This is probably the best Orc spell. It makes the target unit attack harder. This is probably the best spell of the Ogre-mages. Once I played my friend, he had 20 ogres-mages and I had 20 paladins. He had bloodlusted all of his guys and I kept healing but he won.
Death Knight Spells:
Touch of Darkness: This is the basic spell, and it replaces Attack.
Death Coil: This spell just sucks the life out of another unit, and it gives the life to the Death Knight that casted it.
Haste: This spell speeds up a unit to the equivalent of a Ogre/Knight (speed 13).
Whirlwind: This spell reeks! It always moves all over the place and it kills your own units. Whirlwind just sits there rotting, it goes away after a minute or so.
Raise dead: This spell brings life back to the gross looking skeletons that are lying on the ground after a battle.The skeletons don't require farms.
Death and Decay: This powerful spell has a good range, and I use it to destroy towers, other buildings, and large groups of units.
Unholy Armor: This makes a unit invunrable to everything, use it if the other team has exocism. It doesn't protect polymorph. It takes off half of the target's hit points and it wears off in a while.
Paladin Spells:
Holy Vision: This cheap spell lets you see an area of land for a while if u have fog on. When you get paladins you already have it.
Healing: You use this spell to restore health to your units. I don't like this spell. Good to heal gyphons since they cost alot of money.
Excorism: You use this spell to instantly kill a Death Knight or a group of Skeletons. If your opponents a humans don't learn it.
Mage spells:
Lightning Attack: This is the basic attack for Mages. It's the equivalent of Touch of Darkness in Death Knights. It sucks! 0 gold to get.
Flame Shield: This makes a ring of fire go around a unit. the flames will harm anything that it touches. 1000 gold to get.
Fireball: This spell will make a fireball similar to a Dragon's fireball. It wouldn't use it, it wastes your mana. 0 gold to get.
Polymorph: This is a cool spell. It changes an organic unit into a critter. Good to use on Gyphons and Dragons. 2000 gold to get.
Blizzard: This is similar to the Death and Decay spell in Orcs. 2000 gold to get.
Slow: This slows down a unit. I've never used it, mainly because I play Orcs, but when I do play Humans, I never use it anyways. 500 gold to get.
Invisibility: This makes a unit invisible until it attacks.