Natural Selection 2 Interview: The Evolution of a Mod

By Alice O'Connor, Nov 03, 2009 5:30am PST The true scares of Halloween 2002 came not from monster movie marathons, haunted houses or college dorm parties but a multiplayer Half-Life FPS-RTS hybrid mod named Natural Selection, released that night by Unknown Worlds. Low-tech space marines and bestial aliens shrieked and spat out their trick-or-treated goodies in fright as inter-species war with terrifying tones of the movie Aliens raged across derelict complexes among distant stars.

A solid real-time strategy lay on top of the action, with both sides vying for control of key map points including the resource nodes which paid for structures and upgrades. While Frontiersmen served under a commander who essentially played a top-down RTS, the alien Kharaa were ruled by consensus and chose their own upgrades and classes.

The next step for Unknown Worlds will be Natural Selection 2, a commercial sequel announced in 2006. We recently caught up with studio founder and NS creator Charlie Cleveland to discuss progress since then, the path from mod to commercial release, and improving one of my personal all-time multiplayer favourites.

Shack: Who are Unknown Worlds?

Charlie Cleveland: We are a small independent game company based in downtown San Francisco. Our mission is to "unite the world through play," which may seem heady but informs many aspects of our company. We made a game called Natural Selection for Half-Life and are now working on a commercial sequel.

Shack: And how are you funded?

We've received some small bits of investor funding, we license Decoda [a Lua script debugger] and we receive pre-orders for NS2.

Pre-order income accounts for approximately 25% of our budget and that's growing (it's the only funding we're currently receiving).

Shack: What led you to develop a direct sequel to Natural Selection for your first commercial project?

Charlie Cleveland: We're most known for NS and our players like us so it makes sense to follow-up with a commercial sequel. Many players have told us they don't care how good of a game NS2 is, they've played NS1 so much they feel like they "owe" us that no matter what. It's incredible that so many of them have supported us with their voices, time and money.

Shack: Natural Selection 2 started with grand ideas impossible for a Half-Life mod--large outdoor environments and vehicles spring to mind--before scaling down to a game which closer resembles the original. What was behind the reversal?

Charlie Cleveland: Damn, you remember that? Building a company and building a game like [that], both without much money was completely infeasible for us. If we went out and raised $10M from a publisher or venture capitalists I believe we could do that, but had about 5% of that budget.

We still have those ambitions though and I hope one day to be in a position to build towards them.

Shack: You also started by licensing Valve's Source engine before switching to your own 'Spark.' What advantages did that bring?

Charlie Cleveland: We are a small team. Our core group in our office is just now growing to 5 people. We knew that to make a game as ambitious as NS2 we needed technology that allowed a small team to build a relatively big game and one that removed as many obstacles as possible. Our engine is completely real-time lets us iterate as quickly as possible.

For instance, our competitors typically have to wait 30 seconds to an hour to see their art or code changes reflected in game. With Spark, we wait a few seconds or more often, not at all.

Shack: How are you finding having a fanbase already possessing such solid conceptions of how your game should be?

Charlie Cleveland: It's...interesting! Sometimes we feel we can do no right, but other times the responses are heart-warming and wonderful. The trick is to listen to the reason behind their suggestions and not just the suggestions themselves. Often the solution the propose won't work from an integrity, technological or finance perspective, but you can address the problem behind it in a different way. Then everyone is happy.

Shack: You must be anxious about how fans will receive changes.

Charlie Cleveland: Of course! We're always checking feedback to features we tweet or our blog entries. I thought [art director Cory Strader] was going to have a panic attack when we first showed the Onos. We want and need to try new things but we need to appeal to our base too or we're sunk. It's a tricky balance.

Shack: What you consider improvements could potentially open NS2 up to a wider audience but run the risk of alienating an otherwise-assured market.

The Commander's view in NS.

Charlie Cleveland: You hit the nail on the head. I always think that given the difficulty of learning NS, it's a miracle that anyone plays at all. The first time experience is just... painful. Something you don't see you kills you. You build something and someone yells at you because you did it in the wrong "order" or wrong "place" or should be "saving for something else".

The first time I playtested NS on a LAN I watched a player walk up to the Command Station, see the tooltip that told them how to become Commander, log in and nothing. He was just scrolling around the map, probably looking at the artwork and the little blips closing in around his marines. The entire team was screaming but he didn't realize what his role was. Scenes like this make me want to curl up and die. It has to be more accessible.

_PAGE_BREAK_ Shack: Why do you feel the FPS-RTS genre has yet to break into the mainstream?

Charlie Cleveland: I think it's just a very tricky balance. Many design decisions trade fun for RTS players against fun for FPS players so all those decisions have to be made very carefully. Otherwise you have a game that doesn't let players have fun the way they want to play. I think NS just playtested more and took more feedback. The major versions of NS had large changes and we tested many dozens of resource models and features before we released NS v1.0.

Shack: What do you feel is the difference between the Half-Life mod and the commercial game?

Charlie Cleveland: It's tighter, deeper and more accessible.

Shack: What do you expect most players will think the biggest changes to be?

Charlie Cleveland: Heh. More realistic? Better graphics? Or, NS1 with dynamic infestation?

Shack: Plus, of course, Frontiersmen are no longer entirely reliant upon their Commander for equipment, supplies and upgrades.

Charlie Cleveland: The biggest difference is the resource model - marines have their own resources which they use to buy their own weapons and equipment. The Commander still unlocks technology, but players choose exactly how they want to play from those options. There was a bit too much reliance on the Commander in NS1 and it was too stressful. The game will be more fun for more people as well.

Shack: And Commanders will gain a little independence from their players.

Charlie Cleveland: Yes, both commanders have AI builder units they can control to build structures and perform special abilities (dropping mines, glowing brightly to blind players, detonate, etc). Again this was to reduce some of the harsh reliance on the Commander and also make it more satisfying as Commanders can be effective even when the team is inept or confused.

Clan play will still require very tight integration between Commanders and players but public play will function more smoothly.

Shack: What led to granting the Kharaa a Commander too?

Charlie Cleveland: This is really due to the unified resource model - NS1 had a completely asymmetric resource model between the two sides, which made it impossible to balance for all team sizes. As a result, NS was balanced for 6v6 play but small or much larger teams had balance or pacing problems (resources trickling in too slowly or quickly).

In NS2 there are team and individual resources for both teams and this fixes all those scaling problems perfectly. I don't think there's any way to do this without giving the alien team a Commander component. However, like StarCraft, the two sides still play utterly differently.

Shack: As an aside, StarCraft was obviously a big inspiration to Natural Selection. I take it you're looking forward to SC2?

Charlie Cleveland: What are you trying to say?!

StarCraft is the best game of all time in my book, tied only with Chess and Magic: The Gathering. I actually haven't kept up much with SC2 but yes, I cannot wait. Let's hope NS2 is out before then so we don't delay more...

Shack: Have recent strategy releases influenced the RTS side of Natural Selection 2?

Charlie Cleveland: We were inspired by the territory system in Company of Heroes and it serves as the basis of our marine "power grid." This grid means that aliens can destroy key structures to disable entire rooms or even wings of marine technology. There are ways marines can build in a faster, riskier way or they can build in redundancies for safety.

The goal here is to facilitate comebacks and to have shifting strategic value for different locations as the game progresses.

Shack: It wasn't uncommon for Natural Selection rounds to last an hour, or even longer in earlier versions. What sort of round length are you are aiming for?

Charlie Cleveland: 15-20 minutes.

I know many NS players love ['epic' games]. I think it won't happen often in "vanilla" NS2 but I'm absolutely sure someone will make a simple mod that will make this happen. Heck, I may do it. I think it could be done relatively simply and elegantly, probably with a couple hundred lines of Lua script.

_PAGE_BREAK_ Shack: Access to NS2's beta is a pre-order perk--is this another case of essentially getting to play the full game earlier or something more?

Charlie Cleveland: No, this is earlier access than that. If you order the Special Edition, you get the alpha, which won't have all the upgrades, maps, weapons, etc. but WILL be a fun subset of NS2 in its own right. We go further than that too - pre-orders will also get you our technology, as we create it. We were inspired by the Overgrowth guys and how they put out builds every week.

The first piece of this is the level editor, which we are currently testing and polishing up. Our level editor is more inspired by SketchUp than Hammer or UnrealEd and lets you work truly quickly. You can create geometry, extrude it with a few clicks, texture it and put in your lights and see how it all looks for real, right in the editor. If you have NS2 running on your other monitor, you can load up your map in-game and every time you hit "save" in the editor, it hot-loads instantly in NS2.

All our tools operate this way, from building textures, 3D models and even our code. NS2 is 95% Lua script which means you can add weapons or features to the game... even while it's running.

We'll be shipping all the NS2 Lua code with the game which will provide a great launching point for mods.

Shack: Natural Selection 2 mods will be installed seamlessly in-game, correct? Will there be a way for players to ensure a 'vanilla' experience, where marines don't zip around faster than a Skulk, sparking lightning?

Charlie Cleveland: [laughs] You are correct. They will auto-download and install automatically. We expect the mod scene to be huge so we are partitioning 'vanilla' NS2 games and 'modded' games in the server browser. NS1 had an active mod scene (even though players had to hack .dlls!) and we expect it to go absolutely gang-busters this time around. We have some exciting future revelations in this area as well.

Shack: Are any new game modes currently planned?

Charlie Cleveland: Nope, we're not doing this, at least not for v1.0. We expect our community to do it though, or we will add some in a patch.

Shack: The 'fairness' of Steam's royalty rates has been the subject of recent minor furore. With your casual title Zen of Sudoko on Steam and NS2 also headed to Valve's platform, do you have anything to add to the debate?

Charlie Cleveland: I'm not sure what the current rates are for hard-core games but Valve has historically been quite generous with developers, much moreso that most portals/services (and far more generous than publishers).

Shack: Speaking of Valve, you've announced NS2 utilises the Steamworks suite--which aspects are in place?

Charlie Cleveland: We're using their voice support, friends lists and server browser. We'll probably use their anti-cheat as well. It's been great not to have to write these things ourselves.

Shack: What's happening with the "fall 2009" date your teaser trailer gave?

Charlie Cleveland: We were very hopeful but alas. We're not shipping it this fall. We're looking at early next year. Sorry about that!

Shack: What can we look forward to from Unknown Worlds post-launch?

Charlie Cleveland: We will be supporting NS2 for at least a year after we ship it. We want to add new weapons, maps, clan support, spectating, etc. After that, I couldn't say. We'll see how we feel about working on more NS or not...

Shack: Lastly, can the world finally know the secret of the 'Big Unannounced System' you often cryptically teased for Natural Selection yet never revealed?

Charlie Cleveland: I used to be a magician so I know that the audience always want to know the secret! Once they find out though, they realize they wish they never found out. It's morphed a bit but we're still planning this...


Shack: The legend of the BUS continues. Thanks Charlie.

Natural Selection 2 can be pre-ordered now for $19.95, with the added benefits of playing in the beta and early access to tools. A $39.95 Special Edition also packs alpha access, a unique marine skin and the "eternal gratitude" of Unknown Worlds.

Still blessed with an active player base, the latest version of Natural Selection can be downloaded from FileShack.

Click here to comment...


  • I've been looking up progress every so often on this one and I'm very glad to see they're getting close to a release. NS1 was a ton of fun, and commanded a large amount of my time. I still believe that to this day, NS1 is quite possibly the most team-oriented multiplayer FPS games I've ever played. You *HAD TO* work as a team or you lost, plain and simple. There was a real element of teamwork and strategy that you don't often find in team-based FPS's. I hope the changes they're making to allow players to purchase their own equipment and such will not ruin that element.

  • I'm hoping this turns out well.

    NS had lots of really core balance issues that never seemed to get resolved, so hopefully the new model will help. Number of players, maps, commander skill, griefers and noobs could ruin a game... You could have an absolutely awesome fun game, back and forth trading territory, great battles... then the next game was garbage. Unending stalemates. Complete trashings and subsequent server evacuation. Griefers wasting resources or blocking teammates. Crappy commanders. It was a complete crapshoot. When it was good, it was pretty good--a real unique experience. When it was bad, it was bad, as it often was.

    Hard for me to imagine what the new game will be like. NS1 had many changes that seem to be less invasive than suggested in this interview. Those changes had significant impacts to the game, but never seemed to calm down the roulette wheel that consituted the fun factor in the game. The changes here are even larger than NS1 went through. Too hard to tell if it will work, all the old fixes never quite got it right. I'm cautiously optimistic.

    Part of me wishes they'd start by drastically simplifying things. I'd often have more fun playing some of the gimmick maps (siege, Legos, etc) because everyone's job would be simple enough that everyone on a public server could at least be on the same page and playing towards the same goal. I think the complexity hurt NS outside clan play.

  • I don't envy the dev team for this game right now. T

    hey're a small group with a lot of work to do. I don't think anyone is gonna lie and say that NS is the most accessible game of all time. Blending RTS/FPS seems to me like a very very hard thing to do. It's very hard for new people, it's hard to be a commander and since there is no single player component there really is no training involved. You just have to kinda leap into the lions den and go for it and hope you don't get hopelessly frustrated.

    Yes, games tended to go from god awful server bombing 32 players to 0 in the span of seconds, to unbelievable team efforts. Just when you think your team was down and out for good, somehow someway bouncing back made for a huge win. Seige games were fun and allowed for of an arcadey team play.

    On the other side, a good commander is only really good if the team follows his lead. And lets face it, there is always a certain population out there that is not into team-play and prefer to be one man armies. In the Kharaa's case, a lack of team cohesion, dropping the wrong towers, or poorly positioning them, players wasting or not spending their resources, and all the other problems of MP gaming .... there were some huge issues and the solutions aren't really obvious in a lot of cases.

    Good luck to Unknown Worlds, I think many NS1 fans are cautiously optimistic and many more are watching curiously to see future media and the release press/reviews/reactions. Certainly people will notice the amount of respect for this team given their accomplishments with the mod, hopefully that translates into sales. Given how many hours I logged as a freebie mod player, they'll get my pre-order support as a thank you for a great game.

  • i've said it before, and I'll say it again. I am way excited for this. Great interview!

    It brought back all sorts of memories. I blew off all my friends on launch night and stayed up till 5am playing. Some of my greatest gaming memories are from NS. I played in a 4 hour match one time on ns_eclipse. Khaara were kicking our asses, and were literally seconds from winning but me and a friend were able to sneak into the one of the hives in time and started constructing a new base. We were able to get a whole base going before the khaara could attack our other location, it was awesome.