The Abstergo Industries entertainment subsidiary has opened its doors in Montreal, Quebec, using advanced technology to relive fragments from people's past lives. The protagonist is hired by the company to connect with Edward Kenway, a Welsh privateer living in the 18th century. Through his journey, Edward assumes the identity of a rogue Assassin and finds himself at odds with both the Templars and the Assassins.
The game's world is larger than ever before, allowing for seamless exploration in a ship-to-land transition without loading. Players can explore the Caribbean Sea, discovering cities like Havana, Kingston, and Nassau, as well as smaller settlements and uninhabited islands. The protagonist can hunt animals, fish, uncover treasure maps, and even recruit crew members for his ship, the Jackdaw.