If you have play MMORPG, highly possible you have encounter some occasion where you should find an NPC with exclamation mark on their head, right? All of those are to start event in the game. But you will not find it in Guild Wars 2, since whatever you do will relate to dynamic event. Interacting with plant, speaking with vendors, or helping screaming NPC can lead you to certain event. But before you start an event, here is a brief info for you.