The news that XCOM 2 was going release exclusively on PC was a bit surprising, not least because sequels tend to be expansive in as many senses of the word as a developer and publisher can muster. It makes sense, though, when you look at how the PC community reacted to XCOM: Enemy Unknown in the months after its release. As is the PC platform's wont, mods started springing up, and they were incredibly popular.

Perhaps the most popular of all of them, Long War, has had nearly a million downloads on the modding website Nexusmods. It lengthens Enemy Unknown significantly, as well as increases the difficulty and complexity, and adds a few other notable changes to the mechanics. What this told the team at 2K Firaxis was that there was a community out there that very much wanted to tinker with what they’d made.

“It was a little bit of a shock that anyone actually made mods for Enemy Unknown,” says Jake Solomon, creative director on XCOM: Enemy Unknown and XCOM 2. “That’s what drove us to make modding a key central feature to XCOM 2.”

Not only that, but Solomon and his team actually consulted with the creators of the Long War mod during the development of the sequel, getting their input on a variety of things, but mostly focused on tuning the difficulty.

“I think Long War and Enemy Unknown have this really great symbiotic relationship, as I suppose all mods do, where they made a much deeper, much bigger experience, and that’s possible because they built off XCOM, but you have to acknowledge that there’s a large portion of the audience who are more appreciative of what Long War was than what the base Enemy Unknown was," says Solomon. "People wanted something deeper and more challenging, and they finally got the game they wanted when Long War came along.”

With such a complex but tunable game, XCOM presents an interesting quandary to game design: when so much of a game's design can be tweaked and altered, while still preserving the core of the experience, how do you separate the good changes from the bad?

“It’s in your best interest to simply absorb the information without any sort of judgment and be able to say, ‘That’s better.' All I want as a designer is to make the best game possible, so I don’t care who came up with the idea, I don’t care if they insulted my mother as they delivered the idea to me, I don’t care because I’m more interested in ‘that’s a better idea.'"

“In regards to Long War, I’m almost more inclined to listen to them than anyone else because they’re only doing this out of passion. They don’t get paid, and so they’ve clearly put in time and are driven by passion. If the audience is passionate about it, they’ve clearly done some things better, they’ve shown more information to the player, and I’m not above throwing up m y hands and saying good for them.”

That said, there is an ethical concern when it comes to looking at these kinds of overhaul mods. Yes, they might do something better, and while they needed your base game to make their mod, how much can you take in terms of inspiration and mechanics from a mod before it becomes a form of theft?

Solomon has a few ideas. First of all, he tells me, “We wanted to make XCOM 2 in the mold of Enemy Unknown but better, and not in the mold of Long War but better. It still doesn’t come close to Long War in terms of complexity of some things, and certainly of challenge, although I will say that that is the biggest example of us looking at Long War, seeing how people responded to it, and being freed to say ‘I think Enemy Unknown has this reputation for challenge, but it’s only at its best when the player is under pressure and losing resources, and Long War was a really good example of that.’"

“There’s a magic in XCOM that Long War really found, and when you put the pressure on the player severely and more thoroughly, players engage with the systems more and the choices are more interesting," he adds."We tried to expressly make XCOM 2 more challenging than Enemy Unknown. [But] we wouldn’t dare try to take mechanics from a mod that’s done so much for you. Our ‘Legend’ difficulty is meant to bridge the gap until a Long War 2 comes along, because it’s clear that there’s an audience for that.”

While XCOM isn’t unique in having a thriving modding community, it is singular in that any mod made of it is an adaptation of an adaptation. As Solomon puts it, “I’ve never felt, and never will feel, a sense of ownership over the concept of XCOM. It was a masterpiece, and it’s Julian Gollop’s idea, and I don’t have any ego or sense that it’s mine.”

With all this in mind, the development of XCOM 2 was undertaken with the express intent of making modding something that was planned for, rather than wrangled out of the code by passionate modders. This has presented a real challenge for Solomon and his team; it meant that the sequel was actually more work than creating the original.

“You have to really commit to make modding good, and that’s really what Ryan McFall [lead engineer on XCOM 2] did," says Solomon. "We rewrote everything from Enemy Unknown, which was painful. We wanted the game to be very moddable. For us, it was neat to say that when the game comes out, we’re going to give people these mods, but also all the assets we’ve made, all the textures, models, animations, all the code, which especially for strategy games means the design, as that’s in the code, we wanted to give it all to them.”

The team is going so far as to give the modder community a head start. At PAX South, Take Two announced that Long War Studios would have three pieces of mod content ready and available for free when XCOM 2 launches.

The Muton Centurion, a new alien unit that's stronger than the base Muton, is one of the mods that will be available at launch.

Is Solomon worried that he’s basically giving up everything his team has developed for the past few years?

“In the old days, we used to think that everything was proprietary, but if you look at how people operate, the magic of the team isn’t in the content they create, it’s in them--people with skills,” Solomon tells me. “We don’t lose an ounce of value by giving away every piece of content. What’s really valuable is the developers.”

Now that they’ve given away the keys the castle, the challenge presented to Solomon and his team is to outdo those who’ve done so well in the past. With modders being able to more easily generate, 2K Firaxis is going to have to make sure that anything they add to XCOM 2 is going to be worth the price tag.

Another XCOM 2 mod that will be available at launch is a “Leader” upgrade path for soldiers.

“Competition is good for the player, right?” Solomon says. “It would be awesome if people created free content for the game, but at the end of the day we still win, right? People still buy the base game. I don’t have the competitive gene in me, because I understand it’s going to benefit the player. If the player is benefited the franchise is benefited."

"That being said it is interesting to say ‘Ok, there’s all this content out there, we have to find something that we can do as a developer that we can offer to the player that other people can’t do.’ There are companies that are very open to modding, like Valve or Bethesda, and they find a way to keep themselves relevant. In the past, when we made an expansion pack it was because we were the only people who could make an expansion pack. But now a modder could, theoretically. So it’ll be interesting to see what happens.”

And now that XCOM 2 is finished, what did the Long War creators think of it?

“The last email I got from Johnnylump, the lead on Long War, was him saying that the highest difficult was ‘pretty difficult.'” Solomon laughs. “If those guys think it was pretty difficult, we probably dialed it in pretty well.”