In my last post I discussed why video games should be studied, and why the digital humanities is a field uniquely suited to carry that torch. There is one key to being able to properly study a particular video game that I had not addressed, though: the continuing existence of that video game. Unfortunately, the preservation of video games is hardly a straightforward affair, and there are several aspects that must be considered and hopefully addressed when preserving a video game for future use and study.
1) Source code vs. ROM
First, there's the issue of what exactly you should preserve to preserve the game itself. Many people would probably think, "Hey, I've kept around this old NES cartridge of Zelda II: The Adventure of Link. That's good enough, right?" Well, not necessarily and not really. See, the actual file you keep on that cartridge (or on a disc, on your hard drive, in the cloud, whatever), is actually a Read-Only Memory file, i.e. an iteration of that game as software formatted to run in a particular environment (e.g. your NES). So, if you want to save the file that says how the game should function, you want to save the source code, which is something usually only the developer has. And unfortunately, many developers don't keep that around as well as they should once a game has been released, either because they don't care or don't really understand the value of their source code vs. the released product.
2) Hardware & Software
Okay, so let's say you've successfully got a copy of the game preserved that you should be able to play. Now you just need to have kept around something to play it on, or have the capability to modify or build something to play it on. This is pretty straightforward to understand if what you have is something like an NES cartridge: you need the right video game console (or replica of it). But what if you've only saved the software from that cartridge as a ROM file? Well, hopefully you can get an emulator or virtual machine to run it on your computer. And at that, an emulator or virtual machine that can run it as it was meant to run, since you're clearly not running it on the hardware and software that ROM was designed for. So in addition to preserving the game, you have to at least preserve the specifications of what it was supposed to run when it comes to hardware and software.
Speaking of hardware, what about the interface components that define how you interact with the game? Is it adequate to play an NES game on an HD television, when it was designed with CRT televisions in mind? In other words, you want to consider also preserving the type of visualization interface it was designed to be displayed on, or at least replicating what that type of interface would have provided. In addition to the visualization interface, there are also the input interfaces as well, such as a keyboard, mouse, or game controller. To truly replicate the game experience as designed, you really should have the same type, if not identical, methods of inputting your control of the game.
4) Multiplayer Gaming Environment
Multiplayer games get their own bonus entry on this list! The reason for this is relatively simple: when the experience in a game is reliant upon there being a multiple number of players in the game, it's pretty much impossible to replicate the game as designed by yourself. Now, this isn't as much of an issue with games that feature a limited number of multiple players, such as 2 to 4, although it obviously does require having around enough hardware and software to support all those players at once. However, what is truly difficult, and presents a unique challenge in preservation, are massively multiplayer games, such as World of Warcraft, which are intended to have a vast community of players online at the same time. Without the player base, such games are significantly altered in environment.
As you can see, there are a myriad of challenges to be overcome when it comes to preserving video games for the future, some of which I still don't see good solutions for (such as the preservation of massively multiplayer games without enslaving masses of people to keep playing it for you into eternity).