https://www.gamespot.com/articles/the-best-assassins-creed-game-is-free-on-pc-right-/1100-6455586/

If you never got around to playing Assassin's Creed IV: Black Flag, then you missed out on what I'd argue is the best Assassin's Creed game in the series. But today's a good day to try it out: It's now available for free on PC.

Ubisoft is holding a promotion this month to celebrate the tenth anniversary of the launch of the first Assassin's Creed: it's giving away PC downloads of Black Flag. From now until December 18, you can get the game through Ubisoft's Uplay service. And once you claim the game, it's yours to keep.