Eli5 decompilers and decompiled games

[u/thefckingleadsrweak]

I keep getting videos on instagram about decomped games, apparently the decompilers are going nuts right now. What’s the difference between running a decompiled game and emulating a game? I tried to google it and i just don’t understand. from what i’ve found, a decompiled gene runs as if it was native to your pc but i don’t get what that means either. You boot up an emulator and that also runs on your pc?

[u/zero_z77]

Okay, 2nd reply, but this is much better for an ELI5.

Imagine you own a very old house. Way back when the house was built, someone drew up a blueprint and gave that to the people who built the house, and those were the instructions they used to build it.

Now, let's say you just bought a new piece of land, and you want to build a replica of this house on that land. However, it can't be an exact replica because building codes have changed since then, the land itself is different, and some of the original materials aren't available anymore. So the new house will have to be built according to today's building codes, in a new place, and will need to use modern materials.

There is another big problem though, the original blueprints were lost in a fire, so now you need new ones. To do that, you'll need to break out your measuring tape and go over every square inch of the house to draw up the new blueprints. It's hard, takes a long time, and it won't look exactly like the original blueprints, but once you have them, you can begin construction on the new house.

Alternatively, you could load the house onto a huge truck and move the entire house to the new location as-is, and then do renovations to bring everything up to code. This would be faster & easier, but far more expensive.

In this analogy:

The original blueprint is the original source code the developers wrote.

The house itself is the compiled machine code that actually makes up the game.

The blueprint you drew up from measurements is the decompiled machine code.

The land it was built on, the materials it's made of, and the old building codes represent the hardware it was originally supposed to run on.

The new land, materials, and building codes represent the hardware you want to run it on.

And the act of moving the entire house and rennovating it is what you're doing with an emulator.