Kaiserreich: Legacy of the Weltkrieg is an alternate history total conversion mod for the grand strategy video game Hearts of Iron IV (2016).

[3] The Central Powers victory leads to numerous changes from the real world's political landscape, with every country and region being impacted and having altered history.

Timothy Borsilli of Wargamer wrote that Kaiserreich was a "rich, well-researched, and lovingly crafted world" that retained realism and fidelity and was designed for "maximum entertainment value."

He believed that the base game was generally predictable, with player choice not having any major impact on the final result of the conflict due to being grounded to World War II, while Kaiserreich was a mod that "attacks" that problem.

[1] Luke Plunkett of Kotaku shared similar thoughts, believing that while Hearts of Iron IV had limited variation in outcomes, Kaiserreich was a mod that opened an "infinite number of sliding doors moments every time you move," believing that every possible player choice was accounted for in order to increase immersion.

[3] PCGamesN's Joe Robinson echoed similar thoughts to Plunkett and Borsilli, writing that the mod was like a "well-written, perfectly paced war movie, with a slick setup, a rising arc of tension, and an explosive, climactic finale.