This simple little mod gives you the option for your damaging spells and AoE to not harm your followers or magical summons.

When you first enable the mod you will see a message telling you the "Toggle Friendly Fire" power was added to your spell list. It also automatically enables itself, so your allies will be safe to start. Casting the above power, you will get a message saying "Companions will take damage" or "Companions will not take damage" depending on whether the effect was toggled on or off.

This mod does not cause your followers or summons to ignore the default Friendly Fire rules ( http://www.creationkit.com/Friendly_Fire/ ). This was not needed because when in combat, your allies will never turn against you no matter how many times you hit them. This just prevents your spells from doing damage to them.

Other NPC's you hit with spells will still behave as they normally would and turn hostile, or follow the default friendly fire rules linked above depending on how friendly they were to start or if they were in combat when you hit them. This mod doesn't effect any game characters other than your current followers and summons, and your current followers' summons.

Also, since this mod works through a hidden perk system and doesn't actually modify any spells themselves, it should be compatible with any other spell-related mods. Additionally, any mod-added spells with the standard MagicDamageFire, MagicDamageFrost, and MagicDamageShock keywords in their effects will automatically work with this mod with no additional compatibility patches required.