How can a video game with multiple endings have a sequel? [closed]

For example: In Injustice 2

Either you can let Superman win and become Batman his puppet Or you can let Batman imprison Superman.

If Injustice 3 ever happens, will my decision in Injustice 2 matter or will the sequel follow along the Batman ending (as it is more reasonable to me).

The best I think the sequel can do is to let me play along the two different scenarios caused by the two endings.

But what about Arkham Knight ? There are multiple cases but let us consider the simplest one where we can either

Send Azrael to jail Or let him join us

For an Arkham Knight sequel, what will be the fate of Azrael?

Yes!

There are several techniques that the developers of the sequel can use. I will list some down below:

1. Declaring a canonical ending

When several endings are possible, the developers can pick one of them and claim that that is the canonical ending. This is often done when one ending is seen as the "regular" ending, and there is some hidden (and possibly humorous) ending as well.

In that case, the "regular" ending will be considered canon, and the hidden ending is just an easter egg.

The same can be done when one ending is considered the "good" or the "true" ending.

2. Declaring all endings as canonical

Depending on how the previous game works with endings, the developers can pick multiple or all endings and declare them all equally canon. This can be done, for example, if the ending is based on individual characters. The canonical thing to have happened would be that the story of all characters happened simultaneously.

3. Making the events of the previous game a mystery

If the sequel includes different characters, you can declare "what happened before" as a mystery, where certain details are missing. This would imply that several or all previous endings are at least a canonical possibility.

Even if the sequel directly contains one character from the previous game, they can evade talking about the details of the previous ending and thus allow players to speculate.

4. Ignore the effects of different endings for the sequel.

Different endings do not necessarily mean that there is not some common ground between all them. For example, an important character could die. For the sequel, differences between all the different endings are ignored, and the story focuses only on the common ground. In the example, said character would still be dead, but the circumstances of their death would not be elaborated on.

There are of course more possibilities. As other answers have mentioned, the game could allow you to read an old save file and thus determine your ending. Or I'm sure some developers did some other clever things.

There are multiple ways to a sequel for a game that have multiple endings. Spoilers ahead (obviously).

Case 1: Witcher 2 => Witcher 3

The story of Witcher 2 splits into 2 drastically different paths in the end of Chapter 1: you are either going with Roche and his Blue Stripes or you are going with Iorveth and his Scoia'taels. These groups are pretty much at war with each other, so siding with one of them will make you an enemy (or at the very least untrustworthy) for another.

However, the final cutscene of Witcher 2 reveals that this conflict was nothing but a petty squabble, since there is a major war with Nilfgaard starting soon.

Basically, whatever you did in previous game doesn't really matter and will become a glancing reference or some insignificant bonus at best.

Case 2:

Drakengard: (Ending E) => Nier, (Ending A) => Drakengard 2

C&C: Red Alert: (Soviet Ending) => C&C: Tiberium Dawn, (Alliance Ending) => C&C: Red Alert 2

Both of these examples are a bit questionable canon-wise, but I can't give a better one.

The point is: multiple endings split into different sequels. It's a rare and expensive for developers, but it can be done that way.

Case 3: Deus Ex => Deus Ex 2

Whatever of 3 endings of Deus Ex you might have chosen, all 3 of them happened. How? Well, JC became an avatar for an AI god (Ending 1), which caused a collapse of the Internet on Earth (Ending 2), and The Illuminati used that 'Dark Age' to snatch the control over humanity back in their hands (Ending 3).

Personally, I'm not a fan of this one, but whatever, it kinda works.