Ball Lightning is a an electrical projectile spell that launches 3 small electrical spheres that burst after a short distance. Each sphere travels a short distance forward and starts slowing down until coming to a complete stop, then explodes. The spheres are instantly stopped when hitting terrain, though this doesn't make them explode sooner.
The short range limits the usefulness of the spell, but this can be alleviated with the use of a Trigger spell or Long-Distance Cast to launch the bolts at a distance.
Similar to Lightning Bolt, it's easy to harm yourself when using this spell; be careful when casting it near liquids or metals without the electric immunity Perk, especially when using it without triggers or other methods of increasing its range.
The triple-projectile nature of the spell means that it synergizes well with all modifiers, as each is applied to the bolts separately.
Multicasting several Ball lightning spells doesn't seem to add their total spread, unlike how Triplicate Bolt behaves.
A homing modifier significantly increases the damage dealt by the projectiles.