Cốt truyện

The plot is set in a fictional history of real-world events and follows the millennia-old struggle between the Assassins, who fight to preserve peace and free will, and the Templars, who desire peace through control. The framing story is set in the 21st century and depicts the player as an employee of Abstergo Industries (a company used as a front by the modern-day Templars), who is manipulated into uncovering secrets related to the Assassin-Templar conflict and the precursor race known as the First Civilization. The main story is set in the West Indies during the Golden Age of Piracy from 1715 to 1722, and follows notorious Welsh pirate Edward Kenway, grandfather of Assassin's Creed III protagonist Ratonhnhaké:ton / Connor and father of antagonist Haytham Kenway, as he searches for fortune and a mythical location called the Observatory, which is sought by both the Assassins and the Templars. A major plot element concerns the attempted establishment of an independent Pirate republic in the Caribbean.