Imperian has hundreds of help files to help you learn more about the game and how to play.
17.40 Random Encounters
Random encounters are a monthly event in which a special NPC is released into the world. This NPC will randomly find and target characters to attack. Should the NPC target you, it will move to your room, identify you as the target, and attempt to kill you. Killing it will grant you a special prize, based on the type of mob. In order to get the reward for the encounter, you must kill the NPC that are targeted you specifically. If it is attacking a different character and you kill it, you will not get the reward.