On Decompilers

You may have noticed that despite all the talk of decompilers elsewhere recently GameMaker Blog has remained a decompiler free zone. Well, I can’t contain myself any longer so here are a few questions explaining what the situation is.

What is the decompiler?

At the end of January a program was released that enables anyone who has it to decompile executable files created with GameMaker versions 5.3a, 6, 6.1 and 7. The original resources, scripts and objects programmed into the game are retrieved and organised as they would be if you were editing the game. In effect this is a .exe to .gmd/.gm6/.gmk converter.

Why do some people see this a problem?

Many people weren’t too happy at the release of the decompiler. YoYo Games weren’t happy because it shows that the security on their product has been breached and the authors of the decompiler have breached their EULA. Some users of GameMaker fear that their games will be decompiled, their resources and code stolen and that the game could possibly be passed off by someone else as their own work. The chances of this happening to your game are very slim, I am not aware of any games that have been released where the authors have been accused of decompiling a previously made game.

Can anything be done to protect my game?

At the GMC many people [1, 2, 3] have come up with programs which they claim will protect your executable GameMaker files. So far all of them have not been able to live up to their claims, as most of them simply compress the .exe and uncompress it (to its unprotected form) before running it.

Will my game ever be 100% safe?

The simple answer is No. Now hackers have seen that it is possible to decompile GameMaker games chances are they will develop a solution to any anti-decompiling measures that are introduced.

What are YoYo Games doing?

Good question. Apart from “Just don’t do it or you’ll get into trouble” and a threat to take action against those who wrote the decompiler it doesn’t look like YYG are doing much. They promised “we do our best to make sure this can’t happen with future releases of Game Maker AND the website.“, yet no patch has been released almost 2 months after the decompiler was released.

What should I do?

  • Firstly don’t panic. It is unlikely that someone will steal your program.
  • Don’t believe these so-called ‘decompiler protectors’. All released so far do not work.
  • If you are concerned contact YoYoGames and ask them why they still haven’t released a patch or a new version of GameMaker 2 months after the decompiler was released.

Initial source of news: Decompiler announcement at gmnews

14 Replies to “On Decompilers”

  • Uh, so, Legocrazy…

    What kind of “developer” doesn’t make regular code backups? I have several backups of several versions of my game, stored in several different places (USB key, my email account, home PC, etc). If you kept proper backups of your important files, you’d never need to decompile your own code just to get it back.

    And if someone drops a project, but doesn’t mind if someone else takes it on, why wouldn’t that person just give away the source to the new developer? Unless, of course, you’re just assuming that the original author doesn’t care, because (s)he has disappeared into the mist. That’s not much different than ripping a completed game from someone else without permission.

  • So a brief recap of GM7 and YoYo Games and what they’ve done for Game Maker users :

    [1] Implemented Softwrap, the most idiotic registration system on the face of this planet.

    [2]Participated in the creation of GM7 which decompiles any game you’ve poured your hard work into, so that it is playable inside some crappy browser’s window ala InstantPlay (that’s why GM7 executables are so unsafe).

    I’ve heard enough, f**k YoYo Games.

  • @Garion, I would say YoYo Games has turned Game Maker into a profitable business, where as with Mark in charge it was more like a hobby. It used to be pretty much a one man operation where donations and registrations were encouraged but were not the main purpose/intention of the organization.

    Now they operate as any business would, with a main goal of being financially successful. Sometimes this means doing what users want, other times this means making the more appropriate business decision unfortunately.

  • Decompilers can also be a very useful developer tool. Such as if you somehow delete your source or overwrite it and still have an executable.

    They can also be used for dropped projects that people started. Yes that would still be against the EULA, but there’s a lot of great uncompleted games out there, that I know the original creators would not cared if it got brought back up.

  • Yoyo Games are more interested in the money side of things (The website, Instant Play….) and have practically killed off Game Maker

  • Honestly, I doubt if many users have created games that are good enough for people to want to steal them. However, in the rare case that you do have a decent game that you would like to remain closed source, let it be stolen, this may prompt YoYo to do something about it in the future.

    I have only two games (not a big video game fan/developer) out, they are both mediocre at best, they are not open source but feel free to steal them and see how poorly they are programmed.


  • Before you go bothering YoYo Games, someone asked on the glog: “I’m still waiting for new info about GM7.1 … or other way to protect my game against decompiling.”

    Sandy replied: “I don’t know what it will be called, but we are making changes to the way games are loaded. No details yet, but the fix is at least 6 to 8 weeks away.”

    Whether that means there’ll be a GM7.1, I don’t know, make of it what you will.

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