Monday, 21 January 2013

XCOM Guide


Being the nerd that I am, I worked out what I think is an enormously broken research strat:
(Google image search "XCOM tech tree" - this post was originally just for a friend but now it's getting a bunch of views I can't in good conscience link to an image without the creator's permission.)
  1. Start in South America (bonus: instant autopsies and interrogations)
  2. Rush research on alien containment and the stun gun
    • Weapon fragments -> Alien Materials are pretty key too
    • nano-fiber vest is completely useless - sans grenades, it forces you into fire fights which you'll never win early on
  3. Capture a grey, which gives beam research credit
    • Research through to laser sniper but don't worry about about heavy because they're just there for suppression and the level-saving rocket
  4. Capture a thin man, UFO tech research credit
    • Research Nav Computer-> UFO power source
    • This allows the elerium generator and satelite nexus which are awesome as early base improvements
  5. Capture a Floater, basic armor research credit
    • Rush skeleton suit over anything else as soon as you get this
    • Skeleton suits on everyone - best armor in the game until Ghost armor as it gives -10 to hit penalty against you and the grappling hook
    • Skeleton armor also gives easy access to higher ground which gives +20 aim bonus - don't even glance at carapace armor, rush skeleton.
  6. Capture a Heavy floater for Flight credit - you get them really early on one of the terror missions - it's important because they won't appear on downed UFOs for ages
    • Research New Fighter Craft -> EMP cannon
    • Prioritise EMP cannons over Firestorms (new fighters) because EMP preserves resources on downed UFOs and helps to get the resources for making firestorms and all the other stuff
  7. Capturing an alien commander in the underground base is handy because it's the earliest opportunity but PSI is only really useful on the last mission and you only need one psi soldier maxed out - though you might need a backup depending on how aggressive/suicidal your gameplay tends to be.
  8. Finish firestorms, faff around, always try and capture at least one alien per level - sectoids and thin men are really good because plasma pistols and light plasma rifles are awesome.
    • Consider researching light plasma rifles without the plasma credit as they give +10 to hit - but only if you have finished all of the above
    • If you do finish light plasma rifles and you haven't researched the new fighters/haven't captured a heavy floater, plasma cannons are a good stand in weapon but it'll slow you down in the long run
  9. Mid game kicks off - capture a fucking Muton FULE!
    • Plasma research credit
    • again, rush sniper then pistols - heavy plasma is awesome but there's a lot of research that comes through thick and fast in this time and heavies are mainly for suppression and the game saving rocket
  10. Capture a Muton Berserker
    • rush Ghost Armor, it has a -20 to hit penalty, can stealth and has a grappling hook so is way way better than titan armor - which is tempting and awesome but hold out for ghost armor - put it on your medics first because they have no defensive perks
  11. Once you have ghost armor on all your guys and full plasma weaponry, you can just clock the game.  Putting down an upgraded smoke screen on guys in ghost armor in the open gives a total of -60 to hit - that's in the open - in heavy covers it's -100 so they're basically invincible (beware grenades).

    The only thing I research without a credit sometimes is light plasma rifles - they give +10 to hit and with the +10 from a scope makes your rookies, medics and assault guys GODS.

    Foundry projects

    (in order of priority)
    1. (for impossible) - Alien Grenades - so important as will make your grenades one-shot both sectoids and thin men
      On classic, it'll allow your grenades to one shot thin men and floaters
    2. Improved scope - crits are OP
    3. Improved medkit
    4. Improved ARC - mid game you don't want to die for the sake of captures
    5. Ammo upgrade - avoids those situations where you just have to run and pray while your whole squad reloads - particularly useful for suppression
    6. Pistols FTW - they massively improve the utility of snipers

    Officer School

    1. wet work - this'll make your sniper godlike in no time and will rush the squad size upgrades
    2. squad size upgrades - obviously
    3. willpower/level upgrade
      - this is really important on the last mission and when you don't save your rocket launcher for the alien commanders
      - having your psionic do the AoE team buff on guys with good willpower will make them effectively immune to mind control
      - game breaking on the final room of the last mission
      - it'll also give you more psionic soldiers later on
    4. the one that stops your higher level dudes from dying to stray headshots - heavy cover, smoke grenade, skeleton armor?  BAM! Headshot! - does not feel good.
    5. recovery time - I really don't know about this - you'll normally need 2 guys (3 for assault) in each role to cycle in for wounds anyway and I'm not sure how much this really helps.

    What to Build

    Early on, you'll need to make sure you have quite a few of the dodge/aim/the other one things for your shitty interceptors.
    This is much more effective than an early plasma cannon rush as you only really ever want EMP and firestorms - also, avalanche missiles are free and the consumables cost bugger all.

    Early base

    generator -> alien containment -> officer school -> thermo generator ->  foundry -> satellite nexus
    Be careful to leave enough power to build a lift to the thermal, which may mean holding back on the officer school.
    Also plan to have your initial power plant adjacent to the thermal generator with a spot for the elerium generator.

    Broader base objectives

    • 3 workshops, adjacent - get 2 up relatively early, 3 if you can afford it - the refund from construction once you start making EMPs, firestorms, plasma snipers and ghost armor is worth far more than the cost of the workshops
    • Satelite nexus w/ 2 adjacent satelite uplinks - gives full coverage I think (you might want to check that one)
    • No laboratories - I have no idea why you'd ever build them, even without starting in South America - perhaps if you were freakishly unlucky with captures
    • thermo generator adjacent to an elerium generator early - it'll take a while to run out of power once you have this up
    • I "fill in" the little spots between the stuff that needs to be adjacent with the one-of-a-kind buildings
    I do my best to never build plasma pistols, light or heavy rifles and cannons as you can capture them off sectoids, thin men/floaters, mutons/heavy floaters and muton elites respectively.
    This saves an enormous amount of resources - and gets you to late game incredibly fast.

    Satellites satellite satellites - I spend most of my early resources on these and skeleton armor.
    Then I build a firestorm with EMP for each continent which makes interception super easy and preserves lots of money making salvage.


    Make sure to visit the grey market and sell useless junk and corpses that don't do anything - takes a bit of figuring out to decide which corpses are useless - some corpses you only need for one foundry project too.

    It is often worth manufacturing the ingredients for country's missions too.

    As stated earlier - you should capture all of your plasma weaponry except the sniper rifles.

    I would say that most of the money I have used in my games came from the grey market - EMP only makes this better as the ships come down completely intact.
    Likewise, guns over explosives mid game really increases the salvage, particularly in aircraft - blowing up computers or power units is a big no-no.

    Early game team

    • 3 rookies/heavies - frag/alien grenades ftw - "Go die in the trenches, son."
      These guys should do all the dying and I basically bomb the fuck out of any difficult position - fuck salvage - the live captures are far more worthwhile.
      Motto, "see an alien, grenade an alien, closed casket ftw"
    • sniper - scope
      once they have squad sight, keep them safe - most insanely OP class in the game later on
    • assault - ARC thrower
      If you can capture one of each new type of alien when they first appear, it will make the game much easier
    • medic - medkit or maybe scope (since most guys get one-shotted early anyway)
      Medics win the game once they get the mobility, suppression and smoke grenade upgrades
      This dude is trying to last hit after grenades so he can level up
    • I use my assault and medic to finish or consolidate manouvers - I almost never double move and I never put these guys in the front lines.
      I generally have the assault towards the sides so he can come in with cover for the bag n tag.
    Playing on classic and not being an idiot, I didn't lose that many guys with this approach - haven't tried impossible yet.

    I generally capture the last guy on the level by suppressing him so he can't move and whittling him down with pistols to 1 or 2 bars of health for the guaranteed capture.
    Falling back is useful as it'll allow you to advance for a capture without aggroing any spawns further in the level.

    When sectoids do their power up thing, killing the caster will kill the powered up dude - if done with a grenade, the powered up guy still gives salvage as well.

    Thin men are pretty much the most dangerous enemies in the game - they have light plasma rifles which are super accurate and often one shot lower level guys without a crit.
    Their poison, if cast early in a level, will almost kill low level guys.
    They also survive grenades, unlike sectoids.

    So, if you can catch 2 in a grenade blast early, do it, if you can catch 3 with the rocket launcher, even if it's the second turn, it's worth it just because of what the poison will do to you.
    Getting in a drawn out fire fight with thin men is horrible.
    It can be a good idea to take 2 snipers on the agency missions because snipers pwn thin men so hard and there's often a good spot for them on these missions as well.
    If you can grenade thin men, sometimes there will be opportunities for snipers with pistols to both flank for the finisher and be setup for a good sniping spot next turn.

    It's hard to fall back against thin men as well because they can move and fire their poison and it's range is incredible.

    Mid-late game team 

    (starts when you get skeleton armor and laser sniper rifles):
    • heavy - scope
      He has three uses besides sitting in cover and taking a ton of damage:
      • holo targetting - if used to start a round will make focusing a single enemy much more reliable - can make your medic's and assault's light plasma/scope combos particularly deadly
      • suppression - takes a guy out of the fight - good since the heavy doesn't really ever do much damage
      • boom - this is most useful for dealing with floater patrols or destroying the cover of mutons so that your snipers can clean up while the rest of your squad prevents flanks
    • assault - arc thrower
      His plays:
      • sitting in cover beside door ways, getting free hits on aliens walking past
      • resolving flanking disputes - when you're getting flanked by a lone guy, you can run & gun to outflank to a corner next to the target and get a no-cover crit on them for the one-shot
      • if not flanked, he has more defense vs. more aliens so sitting him in cover at a choke point is actually quite safe, especially with skeleton/ghost armor
    • junior medic - scope
      This dude is for finishing kills, providing smoke screens and suppression. His goal is to level up and become a senior medic
    • senior medic - medkit, scope
      He has two utility slots, runs like the wind and has every tactical option in the game.
      Before you get the second slot, stick with the light plasma rifle so that he can actually hit something.
    • death squad - scopes and a fetish for headshots
      the story with snipers:
      • give these guys plasma pistols first
      • move and reload or move and overwatch with pistols if your ammo is fine
      • double tap is better than the killing spree final upgrade because it is more reliable, especially in mid game when you don't crit 60% base chance for 20+ (late game is just silly)
      • skeleton armor, the higher ground defense bonus and squad vision makes for a scary rooftop sniper - you can often swing from rooftop to rooftop too
      • once you have upgraded scopes and plasma pistols, these guys will do pretty awesome damage with pistols so the move or fire restriction isn't such an issue
      • in general, move either your snipers or the rest of your squad, never both in one turn
      • overwatched snipers don't have the penalty to aim later on and will generally get a hit on enemies in open cover for a one shot kill
      • the sensor is awesome but you have to position correctly
        it doesn't aggro whatever it detects
        it is most useful when snipers dash for safe flanking positions - throwing a sensor out further along said flank will prevent your troops from being flanked themselves, allowing you to have only 2 active fronts

    When you first encounter mutons, it's a really good idea to back-peddle because if you aggro two squads you'll usually lose at least a couple of guys and having them come to you also allows for safe captures.

    Mutons use plasma rifles rather than the more accurate light plasma so smoke screens can often protect two guys - just make sure that they're not close enough to be grenaded.


    Basically, damage is pretty useless because your guys will die before they get to a high enough level to use it.

    Rushing tactics seem foolhardy as you will aggro everything on the level and until late game, simply don't have enough explosives to deal with swarms of mutons.

    So, defense and tactical options are what I choose.


    All the defensive options except rapid fire, which makes taking corners really easy.


    The heavy doesn't actually do much damage and is denied light plasma rifles.
    For this reason, you save a lot of research time by not getting them laser cannons and just using them for the suppression, holotargetting combo and massive AoE cover clearing.

    Later on the damage from AoE suppression is really awesome and the massive cover-anhilating rocket shots are more awesome.
    They are the first to move forwards and suppress the most dangerous target (often a berserker).
    I put a scope on them eventually because they are good against mechanicals.


    The only class with actual choices really.

    Reaction shots on attack is bad because it wastes ammo; they'll be in cover and you'll have a -15 aim penalty on top of that - like I said, just wastes ammo.
    3 extra movement is actually very awesome too.

    The next two need to be considered as a pair.
    Reviving critically wounded allies is kinda cool except it really just gives them another chance to die because they'll get one shotted once revived unless you use yet another medkit (which means another turn).
    So, given that you'll be taking suppression, you probably don't need an extra smoke grenade so I'd take 3 medkits and suppression.

    Smoke grenades become hard cover?! I heard there was another option, I just never read it (also psionics do a better job and are easy to level up).

    Two reaction shots combos well with ghost armor but super medkits are more awesome and you generally need the ammo for suppression.


    Sniper rifles have a high crit chance and snipers have high aim; improved scopes give both aim and crit chance.
    See where I'm going with this?

    Your front lines basically suppress most things and smoke grenade themselves if they're over extended.

    The snipers do the actual killing.

    There seems to be an upgrade path focused around mobility and overcoming the sniper's issues inside ships and the like.

    I might consider this if not for the "wet work" officer upgrade - this gives extra XP for last hits.
    Once you've got your super-squishy sniper to corporal and have squadsight, they'll pretty much never take damage and will level super quickly.
    This opens up the squad size upgrades really quickly so you can pack more walking corpses into your flying coffin.

    You can have two colonel snipers on every mission when none of the rest of your guys have passed lieutenant.

    Add to this that a sniper who is higher than an opponent will generally one-shot anything in hard cover and I don't know why you would worry about any other build.

    Even then, there are a couple of things that (superficially) appear to be choices:

    Disabling shot vs battle scanner - disarm their brain pan soldier!!  That and scanners are awesome.

    Executioner vs opportunist - besides executioner implying that we'd need more than one shot and that we might miss, opportunist will solve our mobility problems by one-shoting anything our front line spooks when they advance.

    In the zone vs double tap - in the zone only works against flanked or uncovered and our main purpose is to render cover useless.  Double tap also disposes of sectopods and cyberdiscs rather nicely.

    Ghost armor allows snipers to double-move into a good position safely while also scouting for the rest of the squad - when they come out of stealth next turn, they can either kill everything or kill everything.

    The first sniper to fire will get both shots of double tap off before the aliens move into cover - if you overwatch the second sniper before you do this, they will generally kill the third alien if it's a single squad.

    The plays/Not dying

    Never double move unless it's run & gun to secure a flank or capture with an assault.
    Only advance with half your squad at a time, the rest should consolidate cover and overwatch.
    Don't be afraid to sit tight, reload, heal up and wait for cooldowns.

    Gather around doors with full moves and ammo available before opening them - there is never a good reason to break this rule.

    If you can hear a patrol, back off, reposition and flank them from cover - much better than mindlessly opening doors and walking into the middle of them with nowhere to go.

    Against spaceships, sighting the enemies then backing outside so your snipers can get clear shots is a fantastic way to proceed - especially if they have to walk past an assault that'll get free hits on them too (don't do this against chrysalids or berkserkers - it will not work out  :)

    Also, against the larger space craft, the roof is often a good place to start out as it'll give you offensive and defensive bonuses and immunity to chrysalids and berserkers.
    Buildings are ok for this but can be destroyed so be very careful about becoming a good grenade target - in particular, take note of soldiers on different levels who are still in grenade range of eachother.

    Suppression works against berserkers - if you decide to kill one, do it all in one turn.  Rooftops are a good counter.

    Cyberdisks and Sectopods are other enemies that will always be an open shot - you must focus these as soon as you spot them.
    One of the sectopod's abilities targets a location - you must move out of it immediately.
    The only thing the heavy is actually good at killing is these two.

    Pistols are important early for getting capture targets as low as possible without killing them - once you have improved scopes, the medic is often the best person to do this as they will have a medkit instead of a scope and won't accidentally crit and kill the target.

    Using your heavy to suppress a target that has a good vantage is often safer than killing the target, even if they're the easiest target - because if you fail to kill them, they will kill you with their height advantage.

    Likewise, if an enemy gets caught in a bad spot, using a medic or heavy to hold them in place while the rest deal with more dangerous targets is often a good call.
    Conversely, it is better to suppress well defended targets than to try and kill them - suppression will apply holo-targeting with heavies too, allowing you to dig out that last muton.

    Go to great lengths to avoid becoming a grenade target - the loss of cover is far worse than the blast.
    I've never seen the AI grenade a single target.

    Sometimes using a grenade or rocket to destroy walls or cover is more effective than using it for kills - especially with snipers and assaults that can fire twice.

    Ghost armor is ridiculously good - if you're already in position, decloaking won't even proc overwatch or (for the first soldier's turn) cause them to take cover - decloaking a sniper and getting 2 one-shot crits on a squad of mutons is like XCOM nirvana.
    You can also put the rest of your squad on overwatch then fire with one soldier, which'll cause them to run for cover and take overwatch shots in the open. Hilarious Rex.


    1. The huge problem with Impossible is the early game, particularly the first 4 missions. Your build is about making the early game even harder for an easier late game. It's gonna be ridiculous luck if you can rush ARC and start capturing stuff without rushing beam weapons first.

      Can you pull off the satellite nexus before the end of month two? If you're just relying on the satellite from month one, you're gonna be almost out of countries.

    2. Agreed - my opening game is grenades and heavies.

      The gambit here is using South America and a first capture to get laser rifles in between missions with the beam research credit.

      By not rushing satellites and selling everything on the grey market, you can fully equip with laser weapons in 2 missions - making thin men a guaranteed one shot.

      You can also get the officer training school and wet work which gets your sniper levelled up really quickly - opening up squad size and the wounded rather than killed upgrade.

      My very early game is so brief that I don't actually mention it really - I guess I assume everyone's opening with explosives?