Producer John Davis (Dr. Dolittle 2, Waterworld) is in charge of the project, and recently explained the current plot of the film to Collider. And after reading, and reading again, we still don't know what to make of it.
Davis' narrative follows:
Tom Rothman, the Chairman of Fox said to me, "How are you going to take this incredible piece of IP and make it into a movie?" Right? Because most games aren't movies, so this is the way I did it: The Sims, as you know, you can control your imaginary world, right?
And our movie, a young man, a 16 year old kid or a 14 year old kid and his friend get their hands on this thing called the Sims Infinity Pack, right, which kind of this very strange video game store which was there just for that moment, and seemingly wasn't all that. But what they realize is that they can scan their world in, because this is the most life like, real Sims game ever.
And as they are playing this they are all of a sudden realizing is what they are playing on the game is having an effect on the real world. So in effect, through the game, they are able to control their world. It's wish fulfillment, and obviously it turns against them.
..And definitely there will be somebody coming out of the game into the real world, like "Weird Science" did.
..I think the third act is great, because obviously there is a nemesis, and the nemesis gets his hands on the game in the third act and he's now set up this incredible obstacle course of incredible things that you can only do through your Sims game that our heroes have to go through before the game becomes permanent and they're forever screwed, and they have got to defeat that nemesis. So it's got some big great fun, adventure set pieces, and whatever their imagination is creates the world.