In ArcheAge, events are usually monthly, and more than one may go on at once. Some are modeled after holidays in the real world, such as Hallowtide and the Winter Maiden Festival, and others are set in the lore of Archeage, like the Feastival and the Rum Runner Rapids. Some are random, such as the Riches from the Depth event.
While events happen, one can collect event or festival coins to redeem for prizes. Prizes differ depending on what the event is about. The Marketplace may add in items related to the event topic.