The Formidable participated in the Battle of Quiberon Bay, but despite assistance from fire ships, she was sunk by the Assassin-turned-Templar Shay Cormac in the North Atlantic during the Seven Years' War.
- Historically, the Formidable was captured by the Royal Navy and dismantled in 1768, instead of being sunk during the Battle of Quiberon Bay. It was also the same historical year when the HMS Royal Sovereign, also a British legendary ship, was broken up.
- Like the Couronne, the Formidable used the standard French Man O' War model, instead of reusing the model of one of the legendary ships, such as the HMS Prince, from Assassin's Creed IV: Black Flag .
- When looking through the spyglass, the Formidable does not display a crew.
- It is possible, though quite difficult, to lead fireships to ram the Formidable, dealing serious damage to the ship.