Raids are a battle option in which you can attack a player's garrison. You can raid a random player with the raid icon. Raids use 5 stamina units. Raids will increase your experience, PVP rating, and gold, and allow for collecting dropped items from units.
You may also be raided, which can result in the loss of PVP rating if your garrison is defeated, or an increase if your garrison is successful. If your garrison is defeated in a raid, you do not lose any units that would need to be healed in the infirmary. You can lose or gain gold after being raided. If your garrison is successful, you are given a positive gold amount. If your garrison is defeated, you may lose or gain gold based on several factors, such as rating, units that were defeated, player level, and amount of gold in your possession.