Index -> Glossary -> Raid
Any of your ready units can begin a raid. When you raid from a quest, all ready units on your side join it. You'll attack any opposing units at the same quest but if there are none, you'll attack your opponent's avatar.
Also, a raid is a kind of multiplayer game in which one side has a single-player team. That single player may be a computer AI opponent or it may be a player hosting a raid using an avatar with the Raid Boss keyword.
