In the fabled beforetimes of the early 2010s, Games Workshop made the decision to end the world. Not our world, though it may feel like it at times, but the Old World of Warhammer Fantasy Battle. The long-bearded miniatures game was vastly outperformed by its younger sci-fi sibling, Warhammer 40,000, so in 2015 it was killed off and replaced with Warhammer Age of Sigmar. This new setting, literally built from the shards of the previous one, reinterpreted iconic Warhammer elements and added a whole pile of shiny newness, most prominently the Stormcast Eternals, huge armoured warriors designed to be the mass appeal poster boys that GW felt WFB lacked.
To say it was a controversial move is something of an understatement, and while this isn't the time or place for a deep dive into why, it does help explain why AoS has largely been ignored by the video game industry, while high-profile Old World-set games like the Total War: Warhammer series (which didn't even start until a year after the release of AoS) have still been popping up. Warhammer Age of Sigmar: Realms of Ruin isn't the first video game set in the Mortal Realms of AoS, but it is the first one to make much of a stir.
RoR, to add another much-needed acronym to this review, is a real-time strategy game in the vein of fellow Warhammer RTS (whoops, another one) Warhammer 40,000: Dawn of War. Eschewing base building and resource gathering, each side attempts to capture Arcane Conduits that generate the resources necessary to build and upgrade units, and can have an assortment of upgrades slapped on top which give additional benefits, such as faster resource gathering or the ability to fire at enemies that come too close. Victory is achieved by taking and holding more Victory Points than your opponent so that their score gradually dwindles away to zero, or by decisively destroying their starting camp. The missions in the story-based campaign mode don't follow this pattern exactly, but the basic rhythm of each battle is the same.