Ever since the surprise reveal of Firaxis' XCOM: Enemy Unknown, the internet has been awash with rumours and speculation about how the new game will compare to the 1993 original. At last week's showcase event I cornered lead designer Jake Solomon and came away with three new revelations about the project.


1. There's more than one base. Sort of.

For hardcore X(-)COM fans, one of Firaxis' more controversial decisions has been to limit the player to only one base. However, this perception isn't entirely accurate:

"There's one base, one main base - and that's where your research and engineering takes place," explains Solomon. "You do all you custom base-building there, excavate and add new facilities there. But you can also expand to different continents around the world. Of course, the continent you start on is also important.

"The player says, 'I'm going to start on Europe, or in Africa, or North America'. Then they can expand to different continents with satellite coverage, and you can send your Interceptors to hangar bases around the world as well. So you can still have UFO interception all around the world through hangar bases, but those are much reduced in functionality compared to the main base, which has all the soldiers and all that stuff."

This is significant, because in the old games it was essential to arrange satellite coverage that covered most of the planet. Under the new structure, only your main base gets the detailed "anthill" view, but you'll still have the capability to monitor UFOs and launch interceptions from around the globe.

"In my experience, my first base was always extremely important to me," says Solomon. "With the second and third base, you're forcing the player to re-play that same game. This was just a design thing where I said, 'Either we can make the first base more complicated, or we can stick with the multiple-bases-around-the-world thing'. For me, the second and third base never had as much meaning. They always got the hand-me-down personal armour and laser weapons from the main base.

"We said, 'We can keep everything in the main base, have a manageable number of soldiers which is still very, very high, and then make the main base more complicated'. So we have things like adjacency bonuses: If you build certain facilities by each other, they get new special bonuses. And there are continent bonuses, things like that. We added a lot stuff to the strategy layer, and the trade-off was that multiple bases weren't adding anything."

One final note: Base invasions have been reported as not being in the game, but for the time being neither Firaxis nor 2K will confirm if that is the case. The official line from 2K is, "We're not talking about it at the moment."

There's still hope!


2. Maps aren't randomly generated, but enemy placement is. And we can expect a lot of scenarios.

In the original UFO: Enemy Unknown, the map layout for field missions was completely random. Solomon explains that this won't be the case with Firaxis' approach, but adds that we shouldn't worry about content repeating:

"The layouts themselves are hand-crafted, but we have a huge [selection]. You could not play through a complete game twice and see the same level. They're hand-crafted, but what happens on those missions - what mission type it is, what aliens appear, where they appear - that's all procedural."

Solomon wouldn't be drawn on exactly how many map layouts will be included in the game, but he's at pains to state that there will be quite a few:

"It's very, very, very big. Trust me, my lead artist is a broken man!" he says. "I'm comfortable saying there are more than in any other game in recent memory."

Enemy AI, however, operates in a similar way to the original titles.

"We've got this thing called the Overmind, and that's like the Alien player. The aliens are moving around, doing their own thing. Depending on what alien it is, depending on what type of mission it is, the aliens do different things. Some of them lurk over a body, but a lot of the time they'll be patrolling, moving all throughout the map. We don't spawn them in."


The music is being done by Michael McCann, who scored Deus Ex: Human Revolution

Anyone who played the early X-COM games will remember the extraordinarily creepy music, which made for unpleasantly tense moments as you crept about in the dark, waiting for a Chrysalid to lay eggs in your stomach. The soundtrack to the new Enemy Unknown is sinister and insistent in equal measure... but why does it sound so familiar?

"It's Michael McCann," says Solomon. "He's the guy who did the music for Deus Ex: Human Revolution. He's the perfect fit for us, so we're really excited about him."

The tone of McCann's efforts will also shift according to how the mission is faring, though it won't give away whether something nasty is hiding around the corner of that building you're approaching:

"It'll change based on how the combat is going and things like that. It'll react to what you know."

XCOM: Enemy Unknown will be released in the autumn on PC, PS3 and Xbox 360