Decreases the target's Aggression (inclination to attack). If the target was attacking, they will stop and will revert to 'peaceful' behaviour, although they will still be aware of your presence, and may occasionally turn towards you as if to attack. Attacking them will not dispel the calm effect.
Calm is actually two spells, '''Calm Creature''' , which works on all non-undead, non-Daedra creatures, non-mechanical creatures , and '''Calm Humanoid''', which works on NPCs.
* For Calming only 1 point magnitude is enough for any level, even with the latest patches.
* Calm is useful if you are trying to fight with ranged weapons or spells in a confined area. Calm the enemy, and run out to put some distance between you.
* Calm is basically a crowd controlling effect. Such effects are exceptional for combat in high difficulty games.
* Calm Humanoid is a useful spell when you need to do some unfriendly things to NPCs but don't want to kill them.
One such trick is to steal an NPC's armor by first casting [[Morrowind:Disintegrate Armor|Disintegrate Armor]] on them until it breaks, casting Calm to stop them from attacking you, then finally pickpocketing the broken armor . This is a bit of an exploit, however, so many players will choose to avoid doing this.