Thoughts: Plague Inc: Evolved


If you’ve been on the internet for a little while you might remember semi-ancient Flash game Pandemic, which was released onto the world wide web nearly a decade ago now. It was a game where you controlled a virus with the aim of infecting (and eventually killing) the entire world’s population through evolving a plethora of nasty symptoms and transmission abilities. Pandemic was a minor sensation at the time, consuming a couple of afternoons that I really should have spent working on my Ph.D and giving rise to the now-decomposing Madagascar/”SHUT. DOWN. EVERYTHING” memes. It was popular enough that I am not particularly surprised that someone has tried to make a proper game out of it, for that is what Plague Inc: Evolved is. I am surprised, however, that so little has changed between the Flash version and this paid-for product, because when you get right down it they are exactly the same goddamn game.

This is a distinct problem for Plague, since while the concept was enough to sustain something running on Flash in 2008 it gets stretched pretty sodding thin when you try to apply it to a full-fat game. The way Plague (and Pandemic) work is that you spend most of your time staring at a map of the world. The map is divided into 40-odd countries/regions which are connected by land borders (unless it’s an island) and air and water transport, the latter two of which are visible on the map as little planes and boats plying various routes between different countries. Your virus/bacteria/brain-munching parasite starts out in one of these countries; the only direct interaction you have with it in most scenarios is to pick which country it starts in. From that point on your interaction with it is entirely hands-off and you can only indirectly control how it spreads through investing DNA Points awarded at various intervals into your plague’s evolution.


Now, one thing Plague does have going for it over the Flash version is that the evolution traits available for your disease are much more extensive. Countries and regions are split into various categories — urban, rural, humid etc. — and you can pick transmission traits that make the bug particularly effective at spreading in each environment type, as well as giving it a higher chance of being spread via plane or boat travel from an infected country. You can give it abilities that make it naturally hardier in hot or cold climates, or which give it resistance to drug treatments used by wealthy countries. Finally there are the actual symptoms of the disease, which range from coughing/sneezing and insomnia to kidney failure, dementia and full-blown comas. Adding symptoms is the only way to increase the severity and lethality of your disease, which makes them pretty important in so far as winning the game by killing off the entire human race is concerned. It’s also Plague’s Achilles heel; the symptoms are by far the most interesting and varied category of disease traits, but given the way Plague is set up you won’t be spending any points on them until the very end of the game.

The problem is that the people of Earth are not going to sit passively by while a superbug wipes out civilization. The moment your disease makes somebody cough in the ass-end of Australia, the national government takes notice and puts it on the WHO watch list. Get enough people infected and they’ll actively start trying to cure it. If, god forbid, you actually start killing people they’ll bend all efforts towards a cure and wipe out your virus in record time. The cure counter in Plague increases ridiculously quickly, all but ensuring a game over if you haven’t infected the entire population of the world before it hits 50% – remember, the goal of Plague is to kill absolutely everyone, so if there’s a single uninfected person left roaming the icy wastes of Greenland you still lose. The best way to keep your bug from being cured is to simply not be noticed at all by not manifesting any visible symptoms until everyone is infected. Ridiculously, it is 100% possible to do this. Once somebody is infected they stay infected for ever, and it won’t matter if you have the most infectious bug in the world if you’ve locked the Severity meter at 0 by not taking any symptoms; doctors can’t cure it if they don’t know about it. Your goal isn’t to make a lethal disease, therefore; it is instead to make something that is entirely benign up until the point where you have infected everyone, after which it suddenly mutates into something that gives the world’s population simultaneous brain aneurysms.


The unforgiving nature of the cure counter – as well as the fact that countries will shut down air and sea travel into/out of the region once your plague becomes a full-blown health crisis, although this is less punishing than it was in Pandemic — means that the stock Plague single-player mode plays out the same way every time: you try to stealth infect the world by taking transmission/environmental resistance traits only, and then once you’ve achieved that you ramp up the lethality to wipe out the world’s population before they can get that cure finished. There’s a whole bunch of plague types available – Bacteria, Virus, Parasite – but all except for two of them will play out in this way. If you don’t play them this way you will lose, because that Cure counter is just too overzealous. It’s probably the single thing I dislike most about Plague; the indirect nature of the control you have over how your virus spreads already means that it’s going to have to work extra hard to make sure it doesn’t feel like you have no control, but the fact that the game will kick the shit out of you if you have the temerity to try to do interesting things with the symptoms effectively means that you’re forced to play it one way, and one way only. If you’re interested in actually winning the game, that is.

The interesting thing here is that the developers seem to be very aware of the fact that this strategy is basically the only sane way to approach their game. However, instead of going back and making some more fundamental structural changes to fix the bad design that forces you into making uninteresting gameplay choices, they instead double down on it by having your virus randomly mutate every so often. And by “mutation”, they mean “acquire a random symptom even if you don’t want it”. You can devolve a limited number of unwanted traits, but eventually you’re going to get stuck with a symptom that means your disease gets noticed, which in turn will send that Cure counter creeping ever upwards. This means that Plague Inc. ends up being an almost entirely random experience; the plague spreads randomly, evolves randomly, will be noticed randomly and cured randomly. In fact I sat down once and let a game play out entirely hands-off from start to finish without investing any DNA points into my bug’s evolution. It still spread from country to country just fine and was eventually cured after infecting half the world’s population; I’m not entirely convinced my involvement would have improved its performance all that much.


It’s never a great sign when your control over a game is so limited that it effectively plays itself. In fact it’s one of my pet hates in video games – although one I usually see in the big-budget FPS scene — so you can imagine what I think of Plague Inc. The base game is basically built on top of a giant RNG, for all that there’s apparently a “hyper-realistic” infection model underpinning the spread of the virus; unfortunately this model is never surfaced to the player in any obvious way and requires you to pause the game and go into sub-menus to monitor it, and so of course you never monitor it.1 There’s other games that have been built on top of RNGs and which have been very successful. XCOM and Blood Bowl come to mind; however, these games were all about managing the RNG so that there was a maximum chance that it would produce an outcome favourable to you. By contrast there’s no good way of doing this in Plague Inc; the closest is the rather dull strategy outlined above, and even that’s basically a 50/50 chance as to whether you’ll succeed before a random mutation screws you over.

This is why I say Plague Inc is, at its core, basically the same game as Pandemic: because Pandemic had exactly the same problem (i.e. even if you were playing it “right” it was a complete crapshoot as to whether you’d win, hence the Madagascar meme). Except, of course, Pandemic was just a free and entirely disposable Flash game; Plague Inc on the other hand has been actively developed for at least three years and still hasn’t managed to fix this crippling design flaw in the base game. It’s only once it starts to move away from that core game experience that I started to see glimmers of hope, as eventually you unlock more fantastic plague strains that give you more control. There’s the Neurax Worm variant that takes over people’s brains and lets you pick which countries to spread to; the inevitable Zombie plague where the infection part of the game is simply the first phase and it transitions to sending hordes of zombies around to eat people about halfway in; and a Planet of the Apes tie in that repurposes the zombie mechanics with a fresh spin. To my surprise it was this last variant that was by far the most interesting, as I established Ape colonies, smashed down research laboratories and tried to evade drone strikes. It’s ultimately only a sprinkling of light RTS elements on top of the base game, but even so it proved that there was a lot of potential if only Plague could step beyond the central concept of infecting everyone.


Given that the core game is so shallow, it’s good that Plague does at least try to build on top of it and give it some sort of point. Boneheaded design decisions show through even here, though, as aside from the Apes tie-in these more interesting plague strains are locked away from the player to begin with; in order to access them you have to play through four games with a Bacteria, Virus, Parasite and Prion using the stealth-infection strategy before you can get to the good stuff. There’s also plenty of scenarios on offer where you start with a very specific sort of bug released into a very specific sort of environment, and while I didn’t think these were particularly interesting they were better than the base game and — importantly — all unlock after you complete the Black Death variant once. So it’s not all bad news, but after three years of development (and what, one year spent in Early Access?) I would have expected Plague Inc to have a hell of a lot more to show for it, especially when Pandemic already did a lot of the basic design legwork.

  1. Even the news ticker events from Pandemic have been relegated to a tiny box in the corner of the screen. Meanwhile I get the same shitty popups about the London Olympics and jokes about Half Life 3 every. Single. Game.
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3 thoughts on “Thoughts: Plague Inc: Evolved

  1. lucidor says:

    “The base game is basically built on top of a giant RNG, for all that there’s apparently a “hyper-realistic” infection model underpinning the spread of the virus”

    Somehow I missed the opportunity for common cold first to infect us all, and second to develop the ability to kill us all later, which somehow would transmit all over the world without having to infect us all again…

  2. Zorak says:

    I have to disagree with you on the stealth approach being the only and best approach to winning. Increases in severity translate to increases in DNA points (popping red bubbles gives you more DNA). Sometimes the best strategy is finding a balance between symptoms (gaining you bonus DNA for each country infected) and using some of that extra DNA toward spreading your disease to the hard to reach areas while also investing in slowing down the cure progress. Also, adding lethal symptoms will not only gain you bonus DNA from deaths, it will both reduce the population (which reduces humanities ability to produce a cure) and lead to anarchy, panic and other nasty side effects. All of these things can slow the cure progress considerably.

    These strategies can be further boosted by utilizing the right genes for the right situations. For example, for the spore level you can use the gene that reduces ability costs to their base cost (no upscaling), spend your initial DNA on symptoms and then go all out releasing spores into the air and collecting the bonus DNA from the severity. Then you can start using that to slow down the cure that they will soon be working on and start introducing more and more lethality to slow them down further while killing them off steadily and gaining constant DNA to ultimately use on getting all the cure stopping abilities.

    Yes, there are some random factors and sometimes they can really screw you over, but most of the time there are ways to react and counter most situations if you know how. Even the Madagascar/Greenland situation is not hopeless if you are able to fully upgrade animal migration after all ports are closed.

    • Hentzau says:

      Ooooh, you just reminded me of the gene unlocks, which are another thing I really disliked. Basically Plague Inc. loves locking the things that make it more fun away behind a barrier of pointlessness. I would have been far nicer if all of the genes and all of the plague types had been unlocked from the start, since it would have allowed me to pick and choose the best things about the game and ignore the parts I think are bad.

      And I did experiment extensively with trying to balance symptoms and infectivity. I could never get it right; it seems that even with 70-80% of the countries infected and being destroyed the ones you missed will finish the cure without too much trouble at all. Adding symptoms introduces too much uncertainty and too much risk, making you far more reliant on hefty dollops of luck than you would be otherwise. Perhaps the genes do make it easier, but since they were all locked off for me (I had little interest in replaying plagues I’d already completed just to unlock genes) I didn’t have that option. Stealth by contrast was a relatively reliable method of winning, and since I had to win four times to unlock the good stuff that’s what I ended up gravitating towards.

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