Games that Share Same Universes?

[Tazreale]

Mostly in a different archetype manner. I mean, obviously all the Elder Scrolls share same universe or more or less world.

Also all the Marvels basically share same/similar universe. (That is no brainer.)

Of course some series it is questionable if they share universe like variations of Final Fantasy.

Legend of Heroes: Trails of the Sky and Legend of Heroes: Trails of Cold Steel share same universe. (Actually for best story probably advise to go from Sky and Cold Steel to get full grasp of everything.)

I dunno on the.. Erm... Tales series games. Like Tales of Vesperia and so on.

I mostly mean games that look completely different or story seems completely different but in similar universe. I can only think of two prime examples of this.
Nier series and Drakengard. Nier follows the events of Drakengard 1 ending E(I believe was the ending.) Maybe shared Universe to some extent, questionable probably. Whereas Drakengard 2 followed events of another ending(forgot which one, but people consider Drakengard 2 noncanon since Yoko Taro didn't work on it.)

Better example. Code Vein and God Eater series. They both share the same universe, I don't want to get too spoiler heavy here, but yea. Two different games, with complete different mechanics, within same universe/world. One you are 'vamps/relevants' with Dark Souls feel fighting other monsters. The other is you are Hunters (Monster Hunter Style) hunting Aragami.

Can't think of many others besides maybe Shin Megami/Persona series to some extent, but they have different worlds in some of their games. So not sure how much they really tie into one another. Plus they have other series that is all over place.. Like the dude in old military Japanese attire and it is also questionable with Devil May Cry sharing it due to licensing with one of their games.. (Nocturne.) where Dante appeared/could be recruited.

Disgaea or NIS developers did similar, I guess. Considering cameos of their characters that you can recruit as party members in their later franchise games(Dissgaea,) that ties to their other works like Soul Nomad and Phantom Brave and then some others.

I guess Mortal Kombat is questionable since it introduces characters from other verses. But not really too sure if it can be considered 'Shared Universes'

Others.. Hitman and Kane & Lynch. There are references in one of the games and I think in Absolution you can find the characters Kane & Lynch actually in the game and have option to kill them.

Manhunt and GTA both have references to one another in some of their games back and forth. Probably another good example since in Manhunt you can find some GTA stuff and in one of the GTAs they also talk about the city Manhunt took place in on radio.

 

[Sync]

Circumstantial evidence suggesting that Dragon Age and Mass Effect share the same universe.

There are references in each game series pointing to the other franchise.

 

[Chalarm]

I know Alan Wake and Control are set in the same universe. In the base game of Control there are small easter eggs in the form of data logs that mention Alan Wake but then one of the DLC directly relates the games.

I do also know a smaller frachise between Styx, and Of Orcs and Men. One is stealth like thief while the other looks to be an RPG in the same vein as Dragon age. Both though have the character Styx the goblin as a playable character.

 

[Strange Days]

I am pretty certain the Erdrick and Zenithian trilogies (Dragon Quest) all take place in their respective continuities, with DQ III set before I & II.

The Tales Of series do indeed share the same continuity, people found out Phantasia and Symphonia's maps match up almost perfectly.

I can also think of the Star Ocean series, everything in it minus SO4 IIRC is all a VR simulation/MMO Sandbox set up by a race of higher beings.