Shared video game continuities have existed since before the Marvel Cinematic Universe linked dozens of movies and TV shows that all have intertwining plots occurring in the same universe at roughly the same time. Movies and TV shows aren't the only ones with shared universes though, several video games and gaming franchises inhabit the same universes, often in subtle ways.
Sometimes it's obvious when games take place in the same universe, but other times, it the connections are small details that could easily be missed. Now, we're not talking about crossovers here. Crossovers are something else entirely and involve characters from one franchise appearing in another. This list is concerned with games that seem like separate entities when they are actually happening together in one universe.
Some of these games exist in the same universes at roughly the same time. Many occur at different times in the same universe, though, sometimes hundreds or even thousands of years apart.Not every shared video game universe fan theory is watertight; some have their holes and some are built on sand, but they all have at least some basis in facst. For many fans and gamers, just the idea of seemingly disconnected video games sharing settings adds to their enjoyment. So join in their excitement and check out this list of video games that could actually exist in the same universe.
Assassin's Creed, Far Cry, Watch Dogs, and Ghost Recon
This one is all about the Ubisoft titles. A lot of this theory revolves around the Abstergo brand that appears in three of these four games. This, along with strikingly similar technologies and names popping up across the different franchises has lead many to believe that they all reside in the same universe. In the case of Assassin's Creed and Watch Dogs, Ubisoft has confirmed that they do, in fact, exist in a shared continuity.
GTA V, Manhunt, and Red Dead Redemption
It's pretty well established that the Grand Theft Auto games occupy the same universe, but this theory asserts that two other Rockstar games also share the same overall setting. The fact that the setting for Manhunt, Carcer City, is mentioned by the protagonist of GTA V is evidence of their connection while the appearance of the protagonist of Red Dead Redemption in GTA Online brings this theory full circle.
Counter-Strike and Left 4 Dead
Fans of this theory say that the events of Counter-Strike precede Left 4 Dead. They argue that at some point in the Counter-Strike narrative, the terrorists win and release a zombifying chemical weapon. The main connecting point between these two franchises is the similarities between some of the maps and destinations in each. The resemblances are uncanny enough to convince many that they fall at different spots on the same timeline.
Basically Every Valve Game
If you want to read all the ins and outs of this complex theory, find the details here. Essentially though, it suggests that Day of Defeat, which takes place during WWII, is the first game in a timeline that connects Half-life, Portal, Left 4 Dead, Counter Strike, and more, all the way to Dota and Dota 2 which are set in the distant future (possibly on a different planet).