Spells are created in the spell factory. Upgrade your spell factory to get new spells and more spell capacity. You can upgrade them in the laboratory. They are upgraded with elixir.
Lightning Spell
The Lightning Spell does damage in a small radius. It is used mostly to attack Dark Elixir, destroy defenses, and take out clan castle troops.
Healing Spell
The Healing Spell heals your troops greatly in a small radius. It is used mostly on troops with lots of health.
Rage Spell
The Rage Spell makes you troops stronger, faster, and bigger while their in the small radius. It's mainly used on troops that are slow or to break into a specific part of a base and wreck it.
Jump Spell
The Jump Spell enables your troops to jump over walls. It's used mainly so your troops can reach the center of the base and destroy the town hall.
Freeze Spell
The Freeze Spell freezes the opponents defenses and defending troops. It's mainly used to freeze high level defenses like the Inferno Tower and X-Bow.