The Making Of Natural Selection


Seven years ago to this very day, uber-Half-Life mod Natural Selection was released. Man! Aliens! Man vs aliens, in a real-time-strategy-in-an-FPS-perspective kinda way! In that time, it’s become something of a landmark in terms of just how far you can stray from the source technology (pun not necessarily intended), just how successful a group of a have-a-go home designers can be, and quite how much prescribed concepts of first-person-shootage can be pushed. Developers Unknown Worlds Entertainment are gearing up for the insanely-anticipated release of the standalone sequel (of which the first and second super-shiny images of this post come from – click to embiggen), whose birth depends hugely on how much pre-order interest they can drum up. In other words, if you’re excited about NS2, you should totally pre-order it. It’s going to be a fine and splendid day in PC land when it finally walks our way.

Right now though, given it’s NS1’s anniversary day, we poked Unknown Worlds’ Game Director Charlie Cleveland into providing a little insight into how this milestone mod came to be…

How did NS1 come about? Was it “we want to make specifically this game” or “we want to make an HL conversion?”

The game came first. The concept of playing a FPS or RTS while your buddies play the other and where each of your experiences enhances the other just seems so natural to me. I could never understand why other studios didn’t make them (after making NS, I understood a bit better…there are a lot of tradeoffs). I love FPS games, but I always craved more depth and this seemed so obvious to me.

The only reason NS was written as a mod for Half-life is it seemed to be the most likely way to get this game concept in front of as many people as possible. Counter-strike was becoming huge so it seemed like a no-brainer. It had nothing to do with the engine’s graphics or other capabilities, it was just the biggest platform.


Did you see it as a stepping stone to professional development, or was it more of a passion project?

It was a passion. I didn’t have a financial plan, I just knew that I had to get this game out there. I knew I could never make money directly from NS because it was a mod but I was probably hoping that something good would come of it eventually. I knew it would be hard to launch a new game that was popular and profitable, so I only tried to make it popular. A lot of the work since then has been about making it profitable and sustainable.

How close was the eventual release to your hopes, dreams, wishes and wild, crazy fantasies?

Feature-wise, it wasn’t very close to what I wanted. However, the spirit of the game and feelings I got when playing the game were right on target. It satisfied me and made me happy to have worked on it. I was surprised that even though the marine tech tree was about half of what I wanted, it seemed to provide enough depth for people to keep playing.

Was it an easy or difficult birth?

I have never worked so hard in my life, not before and not since. I literally did nothing but work on the game. I had no social life and I remember noticing many days at a time where I didn’t leave my apartment. About the only time I would leave my room was to go to the bathroom.

I remember my little reward whenever we put out a new release was getting some Thai takeout down the street and then bringing it back to my room and spectating games while people played the new version. It wasn’t very social but it was a huge thrill. Actually, looking back now I think a big part of the success of NS was due to my sublimated sex drive…

Was there a keen sense of something you were missing, not being a pro studio at the time, or was it easy to get hold of experts from the community to fill in any gaps?

I don’t remember experiencing any “lack” in anything. Genres and games evolve so quickly that just building a game usually makes you an expert in that field.

My answer to everything was “take it over myself” or “work more”. That worked great when your team is used to you being a bit of a control freak, but I’ve since learned to let go and trust other people to do stuff. That’s a lot easier to accept when you are surrounded by people who are a lot better than you.

What was the tipping point when you realised it was a success – and how did it change things for you?

We had a big opening night. I think we had 2,000 simultaneous players on Halloween, 2002. I wasn’t able to think about “success” at all though – I was too busy fixing bugs and freaking out thinking that people were going to leave as fast as they came. There were “lag” problems (actually a CPU issue that manifested as increased ping), balance problems and mass confusion. But it seemed to strike a chord with players so I kept at it.

Even since then, I’ve still never felt like we “made it”. It’s been a struggle and many many small steps and never any big markers of “success”. We’ve done a lot of different things to stay alive and grow, including going into debt, making a casual game, doing contract work, etc. Recently things have really started to take off though and now we’ve got a nice office, revenue and a small but very talented team that enjoys working together. It’s always a lot of work and it could still go away at any time, but you have to try to enjoy the journey.

What would you recommend to anyone else considering this kind of route into game development?

I always tell new game developers not to go to school but instead to use that money to build as many games as possible. After college, the first thing I did wasn’t to go out and get a job but to rent a house with friends in Burlington, Vermont and spend the summer building a game. Some unnamed members of our “team” just drank iced coffee and played chess in those three months, but some of us worked very hard and produced almost nothing. The experience of that though was invaluable.

After we had nothing to show for our work, we started the project over again with a slightly different team. After that failed, just two of us decided to scrap our 3D espionage action game about feminism and religion and make a stupid Star Control clone with Play-Doh creatures in an aquarium. That game, we finished! It’s been one foot in front of the other ever since.

Any sense of what makes a mod successful or unsuccessful?

One thing that helped us tremendously was releasing pieces of our game before the whole thing was released. This was in the form of a “technology release” which included some distinguishing features and tech in our game (Commander Mode, and a particle system tool which Half-life didn’t have) along with all our level textures. What we had was interesting and high-quality enough that it got a lot of press attention on it. That helped make our launch much stronger but had an even better side effect – it attracted talent to us. Once we showed people what we were capable of (it has to be good!), we got mappers and artists of all kinds to help us build the rest of the game.

Also, you must listen to community feedback. What we learned is that you don’t want to incorporate players’ suggestions directly though – that would make the game incoherent and appeal less to people. But listening to the hidden frustration or problem behind the suggestion and then addressing it in the way you know that fits your game the best is key.

Finally, we learned to make memorable elements. Your releases don’t have to be bug-free or perfect, but there must be elements that are top-notch and distinctive. For instance, NS in public play didn’t always result in a fun game, but when Commanders and Marines worked together, the experience really shined and people were won over. I always heard from players how awesome the first Onos encounter was, especially when they realized that was a player. These moments seemed to burn the game permanently in their minds as unique and exciting. I’ve often thought that if a game had a half a dozen memorable experiences like that, your game is done.

Thanks, Charlie. So that’s NS1 – but what of the rather splendid-looking NS2? Official words ahoy!

This Halloween marks the 7th Anniversary of the first public release of the original Natural Selection! To celebrate, please find below the first screenshots from Unknown Worlds’ Natural Selection 2. Natural Selection was the most popular independent mod for Half-life and is now being re-made as a commercial sequel which will be released on Steam in 2010.

The second screenshot shows a squad of marines attacking some wall-running Skulks and a flying Lerk. The first shows the view from a Skulk with his trademark “bite-cam”. Skulks use vent systems to ambush, attack and confuse unsuspecting marines.

Natural Selection 2 started life on the Source engine but is now running on our proprietary “Spark” engine. Spark allows small teams to make sophisticated games relatively quickly and without waiting. All changes to art, levels and even code are seen instantly in game.

We will be releasing the first piece of Spark (the level editor) in November to everyone that pre-orders NS2, so fans can start building levels. Unknown Worlds will be purchasing the best community levels to include in NS2. We release our other tools in the same manner before the game comes out as well.

Game information
Natural Selection 2 is a multiplayer-only first-person shooter game with real-time strategy elements. It pits marines versus aliens in shifting, strategic play in claustrophobic indoor sci-fi environments. The game is designed around four “pillars” – Real-time Strategy, Two Unique Sides, Dynamic Environments and Unlimited Replayability.

It is now being offered for pre-sale and is being funded largely by fans.


  1. Tony says:

    Oo-oh, those NS-makin’ bones.

    Liked the concept, was shite at it. Like most things.

  2. Cutman says:

    Wasn’t NS2 supposed to be released Q3 of this year? Sucks that they didn’t make it in time. (early) 2010 is good enough for me though.

  3. Wulf says:

    This is a Wulf do want.

    It’s incredibly satisfying to tear up some human marines, it really is. Just think of them as Gears of War or Halo gamers, the manner of dull-witted people who’d choose to pick a bloke with a gun over a fantastical alien race. With that image in mind, a little bit of OMNOMNOM here, some viscera there, topped with a little jugular tearing, and spiced with bodies swung around by the extremities of their limbs. Such a thing quickly becomes a personal ambrosia, a hugely therapeutic thing of beauty.

    Ohhh yes.


  4. Stabby says:

    Pre-ordered this as soon as it went on sale. Mmmm shiny black armour.

  5. Vinraith says:

    So it’s an asymmetric multiplayer game? Interesting. Is there an SP component?

    • Vinraith says:

      Fair enough.

    • Alexander Norris says:

      I’m sort of surprised there are people playing games these days who haven’t heard of NS, but then I guess that being a part of an actual mod team does somewhat skew my expectations of what people should and shouldn’t know.

      Anyway, a single-player campaign for NS would end up being much like the single-player for Flashpoint or ArmA – you’d start off playing an FPS and end up playing an RTS, and I’m not sure that’s a good thing. Plus, you’d take away the good bit, which is the joy of surviving a Khaara ambush with your squad because you focus-fired and the Commander was timely in the dropping of supplies.

    • Vinraith says:


      It’s entirely possible I had heard of it, but if it lacked a single player component I’d have written it off and likely forgotten about it. It sounds like a very neat multiplayer game, it’s just that personally I don’t buy games whose only mode of play is adversarial MP. I’ve got nothing against it, but in practice I’ve learned that I don’t enjoy that kind of thing for very long.

  6. caramelcarrot says:

    Posting to just reiterate what an amazing game experience NS1 provided (those sort of narrative experiences that developers try to aim for) and that I’ve pre-ordered NS2.

    (@Vinraith – There’s not an SP component in NS1, and I doubt NS2, the point of NS is the multiplayer teamplay aspect)

  7. kedaha says:

    I loved NS1 beta, but the more they developed it the more I fell out of love with the game.

    Pity, as it’s the game that got me into using voice communications and the first online game I played to demonstrate dynamic teamwork on pick up servers.

    • Pod says:

      I wsn’t in the Beta, but was there from release day 1, and I agree with the sentiment: The more game modes they added and the more they tweaked the marine side to make it easier to play without serious teamwork, the less fun it became :(

  8. Tom says:

    Is that vid pre-rendered or the engine-in-action?

  9. Hobbes says:

    Vinraith: “…Natural Selection 2 is a multiplayer-only first-person shooter game…”: so only MP.

    It looks amazing, and if it’s anything like NS1, it’ll be indie game of the year 2010 (hopefully).

  10. Linfosoma says:

    The video is in-engine.

  11. ChampionHyena says:

    Ahh, Natural Selection. A game I used to spectate feverishly because I BLEW SO DAMNED HARD AT IT.

    Still. I love the concept and the execution and the distances to which they stretched GoldSrc. But how will NS2 fare without the built in HL community behind it…?

  12. Scythe says:

    I played NS 1 from its very first release right up until the Aussie community kinda wilted. NS rescued me from my CS-induced torpor and made for an incredible team-based multiplayer game. It still ranks as one of my favourite MP game ever.

    I couldn’t be more excited for NS2. They’re without the typical marketing budget of most big games so they’re almost entirely dependent on word-of-mouth. If you know someone that you think’d enjoy NS2, let them know.

  13. Starky says:

    Well it’s in-engine only so much as any machinima is, it’s clearly hand animated and has some after effects.

    Still, the engine looks pretty going from some of the vids on the NS website.

    I’m trying not to get too excited about this game though, I utterly loved Natural Selection, I’d estimate i racked up over 500 hours playing that mod.
    Playing endlessly on the Yo clan servers, the Brys servers and a few others, and my own clans server.

    I remember the horror of coming across one of those players that utterly decimated as fade – and my utter joy as one day I realized that I had -become- one of those players. A fact you came to learn when when you played the question of “who’s gonna save for fade?” is asked, and right away other people say “Starky is” (or Nephy as I used to use back then too).

    The best and worst thing about NS though was it’s learning curve.

    It wasn’t that the game was hard to learn, it wasn’t.
    It was that any difference in player skill would really swing a game. All it took was one good player and a team could dominate or be dominated.

    The closest thing I can link it with is something like Defence of the Ancients, where having one player who’s maybe only slightly more experienced/skilled than the rest in the game can shape the whole game, and turn a balance game into a “there’s nothing we can do against them” game.
    NS that could happen 10v10, one good player could win or lose the match for a whole team. Especially on alien.

    Anyway the reason I’m trying not to get too excited, is I doubt that they can recapture that magic – it was the community as much as anything, as well as the leeway and forgiveness that comes with a game being a freemod.
    We put up with a lot of bad patch choices.
    A lot of horrid balance moves.
    A lot of reinvention, and fiddling, and problems, bugs and errors – a lot of 2 steps forward 1.998 steps back.

    I just hope that if they do a combat (co_ or lite) mode along side the traditional NS maps they balance them separately (different damages and health levels and the full 9)
    Because as fun as combat was, it did more damage to ns_ game balance and fun than anything else.

    Oh and siege maps – must have siege maps.

  14. Tom says:

    Holy smokes

  15. msarge says:

    I loved NS back in the day, and were it not for my extreme lack of money, I would have already pre-purchased NS2, if only as a thanks for all the fun I had with NS.

  16. D says:

    I would pre-order immediately if I was sure to get it on Steam when released. These guys should get that worked out with Valve asap.

  17. Redford says:

    Many people from the NS1 community are on-board for NS2. Rest assured that people with NS1 experience will, in some way, help shape NS2 and make it a better game for the experience gained.

  18. The Fanciest of Pants says:

    Can’t wait.

    Also attention all indie devs; this is what your trailers should be like.

    • Henrik J says:

      Not to take anything away from what sounds to be a fun game, but there was nothing in that trailer that hasnt been done a million times.

  19. Tei says:

    “I always tell new game developers not to go to school but instead to use that money to build as many games as possible. After college, the first thing I did wasn’t to go out and get a job but to rent a house with friends in Burlington, Vermont and spend the summer building a game. Some unnamed members of our “team” just drank iced coffee and played chess in those three months, but some of us worked very hard and produced almost nothing. The experience of that though was invaluable.”

    Thats it.

    People want to build a MMORPG as first project. And that is a horrible flawed idea. Your first project must be a Tetris clone.

    Then make 1 mario clone, 1 absolutelly barebones FPS shotter, 3 simple puzzle games…

    With only one project you learn tons of things about a single thing and have nothing to show. With multiple projects you learn tons of thinga about tons of things, and you have tongs of things to show.

  20. zornbringer says:

    natural selection was with no doubt the best looking mod for hald-life. it even looked better than the half-life game itself. your leveldesigner/s are real masters. didnt play it that much though. i didnt have internat at the time and on lans we were only 4 players which was a little less for NS, so we didnt play it that often.

    i didnt really get the commander mode as well. i always had the opinion, let this be a pure shooter, no one needs that strategic element, but in fact this was of course one element that had NS stick out from other shooters.

    i wont pre order though. it looks pretty sweet and im sure it will be a lot of fun and the price is more than ok, but few mmo hypes tought me to never pre order anything in my life again.

    sure gonna take a look at it when it comes out.

  21. westyfield says:

    Any game in which you can see your own teeth is fine by me.

  22. CMaster says:

    Loved Natural Selection. It was the game that really got me in to online multiplayer, got me realising that team-based games could be fun (having liked the idea but found TFC and CS pretty lousy). It was also the approximation of a game idea I’d had in my head for ages, an RTS where you units were real people. (Although my in-head vision was always an MMO, even before they existed).

    NS2 I can only hope will be great. I don’t know if I could get hooked again like I did before. Still, the atmosphere, depth and variety that NS had was something I haven’t seen in any other MP game. Sadly, it had a couple of unresolved issues that never went away, and some that grew as time went on. First was the problem that in general, playing as Aliens was never as fun as the humans. One was that the game was only ever balanced at 6vs6 and going even 1 either way had a noticeable effect – and any more than that the game was almost a forgone conclusion. Also, as the game pushed through into 3.0 and beyond, while it was tightened up a lot, the drive to balance and moreover prevent the game from stalemating actually undermined it somewhat. With round lengths shortening to under half an hour and fortifications being neutered, there was rarely any sense of achievement in seizing an area and epic struggles had largely gone away.

    Also “my sublimated sex drive… ” – his sex drive went from a solid to a gas?

    • Glove says:

      Interpreted as “instantly evaporated from an appreciable amount to nothing”, I do believe.

    • Noumenon says:

      “Sublimated” is Freudian jargon for transforming your sex drive into a socially acceptable drive like sculpture. It actually makes a bit of sense evolutionarily speaking as if you’re a young male your best approach to gaining status is to make something difficult and impressive that signals your talent. See “The Mating Mind” by Geoffrey Miller.

  23. Vae Victus says:

    I loved NS back in the day and played the crap out of it. If you like TF2 you should keep an eye on this one. Not the best comparison, but they are the only two games I’ve played online that really force people to work as a team or face getting owned.

  24. Heliocentric says:

    I’m sat in megadebt post a degree pondering whether i should buy a premium version of a game which isn’t out and has nothing extra with it.

    Add that what ever i buy i’ll be getting 2 copies due to my partner and i having such an affection for the mod.

    On wanting it on steam i’m split, i love valve games on steam. The cross game server browser, the patching and… Well thats it. Impulse has the same patching and the friendslist works with non steam games.

    So while i love steam as a platform, i don’t actually want my games locked to it, not least as steam boots slower with every game i add to it.

    I’m wary of buying ns2 with no assurances of drm or activations but i know the game will be quality.

  25. js says:

    Natural Selection, like Alien Swarm, Max Payne Kung Fu, etc., is a feature-complete mod that is better than most retail games – there’s a lot of new ideas, ideas that are implemented well, tested well, and can stand up to the test of time.

    There’s still a lot of people playing it, and they’ll tell you the reason they do is cus it’s just that good, and the commercial games are just that bad. I almost feel guilty that I don’t (was a top alien player), but I’ll get back in come NS2. It’s also no coincidence that I also still played Deus Ex, StaCraft.

  26. jsutcliffe says:

    Wow — seven years since NS1? That’s almost hard to believe. I loved NS through the 1.x versions, but the community I gamed with went to hell after that. I’m rather looking forward to NS2 though. I especially like how they seem to be continuing the “mod” mindset, with the release of mod tools so level designers can get to work.

  27. Termina|2abbit says:

    NS1 is by far my favorite online game, I’ve been playing on and off since ’02. NS2 looks amazing and I almost can’t believe its coming out as it was considered vaporware for so long. The skulks look kinda big in the screen shots though. I hope my favorite alien class hasn’t been changed too much!

  28. Comprox says:

    I know it’s not streaming, but here is a link to every song FFT (and others) made for NS: link to

  29. PHeMoX says:

    It sounds great. The new infection stuff look sick, dynamical and all.

    Definitely sounds like a great game to me, now I hope for a speedy release, because boy do they take time. (no critic, just observation… the best things always take so much patience. )

  30. airtekh says:

    This is my favourite Half-Life mod by far, and one of my favourite multiplayer games ever. I stumbled across it late 2002 and was bowled over by the sheer weight of ideas in it. Never before had I seen so many fresh ideas crammed into the cliched Alien vs Marine setting.

    I sincerely hope they can recapture the magic with NS2; and that they sell a truckload of copies to boot.

  31. Comprox says:

    I know it’s not streaming, but here is the entire FFT song collection (as well as some non-FFT songs): link to

  32. Sunjammer says:

    Kinda tough to create good levels without being able to playtest them, but hey, cool idea.

    I loved NS, even though i hated to play it. Does that make sense? I tried getting into it and it was always a pain, but it was one of those games that just seemed like it had everything RIGHT on a philosophical level. It just depended so much on good players who understood it, and those were few and far between.

  33. Starky says:

    I for one just hope that NS2 has a new alien.

    A scorpion that hovers without wings!

    (call back to a old NS community meme).

    • jsutcliffe says:

      It’s “scorpian,” and it hovered without flapping. Get it right! :P

      God, I hated that meme. I don’t know why I’m correcting you, other than to show I’m old skool ^^

    • Starky says:

      Bah, close enough.

      I too also hated the meme, which is probably why I didn’t remember it correctly – I just didn’t care enough too.

      Then again I pretty much hate all internet/game memes, I’m joyless like that.

    • CMaster says:

      I’m pretty sure it hovared too.

  34. Stabby says:

    Check out the dynamic shadows and lighting in-game. No pre-rendered or compiled stuff in this engine :D And no compiling models, maps, anything. With Lua, they can make changes and it updates in-game instantly. Seems like a modder’s dream.

    link to

    The good stuff starts around 1:30.

  35. Indiana says:

    verb |ˈsəbləˌmāt|
    1 [ trans. ] (esp. in psychoanalytic theory) divert or modify (an instinctual impulse) into a culturally higher or socially more acceptable activity : people who will sublimate sexuality into activities which help to build up and preserve civilization | he sublimates his hurt and anger into humor.

    • Noumenon says:

      You woulda saved me some typing if you had used the “Reply” button so your post appeared higher up.

  36. trdbglr says:

    What can be said about NS that hasn't already be said except that it's Halloween and I'm not drunk and/or dressed up as Ayn Rand (best Halloween costume ever).

    No, I never really played NS really, though I am optimistic about NS2. I'm like an anti-strategy gamer. I don't like mixing FPS w/ RTS, though I'm sure NS is a good game. Great style.

    That said, I loved this interview. Guy graduates from college, and just gets right to work on something he loves (and masturbates a lot apparently). Kudos to him (you), and kudos on making such a well-loved game.

    Call me crazy, but I'm pretty sure that most (or maybe half) of the most revolutionary multiplayer FPSs have been mods. NS, TS, CS, TF(C), Action… It would seem that the best place for the free-thinking developer (if we're talking multiplayer) is the mod/indie scene. The larger developers can't afford to take a risk on something like NS, and a modder basically has all the engine work done for him/her already.

    Naumachia looks like the same kind of deal.

  37. Erlam says:

    “A lot of reinvention, and fiddling, and problems, bugs and errors – a lot of 2 steps forward 1.998 steps back.”

    I think this echos some of my feelings during the middle of it’s lifespan – basically one patch you’d have 80% alien wins, then the next you’d have 70% marine wins, then it’d be 65% alien wins… etc.

    that said, it’s probably the most fun I’ve had in a multiplayer game in ages. Setting up a perfect ambush on the marines, or holding out just long enough to take down a hive, all great memories…

  38. Stukov says:

    As a good ole FFT member and former nsR DJ, I may have some of those songs laying around if anyone wants them…

    • Stukov says:

      of course, I could also read Comps post and see they’re already here. Damn him…oh. And uh. Go NS2.

  39. Schmung says:

    Good read. The stuff about trying to balance the game rings very true. It’s a total nightmare of an experience and one of the hardest things to do right IMO because you’ve not got the resources numbers wise to run huge scale tests of you’re working off word of mouth and testing experience with very little hard data. As much luck as it it is judgement IMo

  40. Pod says:

    I honestly don’t understand why they made their own engine, rather than saving tonnes of time and just using another one.

  41. jsutcliffe says:

    Anonymous Coward said:
    I honestly don’t understand why they made their own engine, rather than saving tonnes of time and just using another one.

    I think it's because they needed particular special effects or behaviours, e.g. having the kharaa goo dynamically expanding on surfaces in kharaa-controlled areas that Source (which I believe they tried first) couldn't provide, and also that the cost of a good commercial engine is likely a barrier for a small team relying on fan support to make ends meet.
    I suspect there are also benefits to making your own engine that probably shouldn't be overlooked — you can build in the features you want to include, and not bother with things you'll never use which presumably makes the engine more efficient. It's analogous to building your own PC or buying a prebuilt HP or Dell that's bundled with lots of crap you don't need. I'll bet the Unreal Engine (which I pick since it's so popular, and expensive) has many features that just aren't relevant to most games that use the engine and just sit there consuming RAM and CPU time.

  42. noobcake says:

    I remember the first time I played Tremulous — it was supposed to be based on Natural Selection. This is the first time I’ve seen NS…looks amazing.