A lot of us want to share our favourite video games with our children (or nephews and nieces in my case), to the point that some people are thinking about bequeathing their collections via wills. Companies are even competing on this basis. When Valve said that your children cannot inherit your Steam library, GOG said that they would honour customers’ wills as long as they had court orders to back it up.

But apart from legal barriers, there are also technical hurdles to passing games on to future generations, which are far more challenging. Consider the fact that very old Windows games are already unplayable on newer versions of the operating system. This trend will only accelerate as PC hardware evolves from x86 to ARM, RISC-V and beyond.

It is even worse with consoles, which get discontinued and games that are exclusive to those platforms become unplayable. For instance, you cannot play PS2 games on a PS5, or GameBoy games on a Switch.

Last year, the Video Game History Foundation, along with the Software Preservation Network, conducted a study revealing that 87% of old games are at risk of being lost forever. Because the games and the consoles required to run them are increasingly hard to come by, the researchers often had to travel long distances to libraries that had copies; something that will become impossible over time as old consoles stop working.

Obviously we cannot expect companies to keep supporting games forever on every platform. Over time, the player base shrinks and companies need to move on and develop new ones if they want to stay in business. That is where open source comes in.

When the code is available freely for people to inspect and modify, they are able to change it in interesting ways. Consider the original Doom, which developer John Carmack released as open source in 1997. While he did predict that fans would port the game to various platforms, the community far surpassed his expectations.

Today it is practically a sport to get Doom running on various platforms, including ones that were not designed for gaming. You can play it on a graphing calculator, pianos, printers, ATMs, thermostats and lawnmowers. One programmer even got it running on a pregnancy test. Other creative individuals have got it running virtually in other games such as Minecraft, or even within itself.

Nor is this an isolated case. Other popular old games that were later open sourced, such as Quake, Wolfenstein 3D, and Canabalt got ported to a wide variety of platforms and operating systems. It’s amazing what fans do for games, if only they have the freedom to do so.

It is a common misconception that open source is unprofitable. After all, if anyone can copy a game for free, why would they buy it? Yet, we do not observe this happening in the real world. Cracked versions of almost any game are available from day one, yet people choose to buy them. Some do it for the convenience, such as automatic updates, cloud saves and other creature comforts. Others do so out of a desire to compensate developers for their work.

The same logic applies to open source games. For example, games like Mindustry and Thrive have both seen commercial success even though they are available for free.

In fact, there is a strong business case to be made for the benefits of open source. John Carmack said that he had a very easy time releasing Doom Classic for iOS devices in 2009 because of work done by others on his code. Making the code public also means that bugs will get fixed much faster, which would improve players’ experience and garner goodwill with them.

Companies can also leverage open source to find employees more easily. Imagine fans who are in school or college right now. It’s their dream to make games when they graduate. If they are able to tinker with the source code, they would essentially be training themselves for the job. Companies could simply look at their contributions on GitHub and hire employees who are not only passionate about the games, but already familiar with the codebase and can hit the ground running.

If this is not convincing enough, there is another option. Companies can make a profit first and then release their games as open source after a few years, rather than make it public from the beginning. Those free games can get people interested enough to buy the sequels.

Games are simply another art form, just like books, music or paintings. The difference is that games require platforms to play them, and those platforms keep changing rapidly. Making them open source will keep playable forever as long as someone finds them interesting. Exceptional game designers will be remembered and respected just like the great authors, musicians and painters of old.

As we have seen, sharing knowledge freely is beneficial for everyone involved; the players, the developers and companies. It will also benefit future generations by letting them play and enjoy our favourite games.