XCOM: Enemy Within: Impossible Ironman Guide XCOM EW Impossible Ironman Guide Contact me at firstname.lastname@example.org if you have questions Last Updated on 08/24/2014 Table of Contents 1.0 Maps 2.0 Classes 2.1 Sniper 2.2 Heavy 2.3 Assault 2.4 Support 2.5 MEC 3.0 Early Game (1st month) Strategies 3.1 Moving Hunker 3.2 Mind Meld Exploitation 3.3 Focus Fire 3.4 Shoot and Smoke 3.5 Bullet swarm and hunker 3.6 Surprise! 3.7 Batman 3.8 Overwatch Camping 3.9 Fall Back 3.10 Fodder 4.0 Mid Game Strategies (2nd month+) 4.1 Hunker and Snipe 4.2 Lobbing ungodly amount of grenades. 4.3 Mimetic Skin Abuse 4.4 Flaming MECs 4.5 Suppression March 5.0 Game Ending Strategies 5.1 Unending SHIV Onslaught 5.2 Mimetic Snipers 5.3 Sniper MEC Squad 5.4 Carpet Bomb 5.5 Assault Rain 5.6 Mix of Everything 6.0 Walkthrough 6.1 1st Month 6.2 2nd Month 6.3 3rd Month 6.4 4th Month 6.5 5th Month 7.0 Miscellaneous Tips 8.0 Alien Specific Strategies 1.0 Maps The maps you get in your 1st month will determine how easy your impossible ironman experience will be, or if you'll even get past the 1st month. The reason for this dependence on map draw is because you have absolutely no long-range capability so you will lose in every map that prevents you from safely closing the distance. After the 1st month (specifically after your 1st squadsight sniper) maps become completely irrelevant because every map becomes winnable. Check out the strategy section for more details. General rule of thumb: 1. If a map has 1 building in the middle with a low rooftop (you can see the square right under you when you go to the edge), the map is winnable and is an easy map. 2. If a map has lots of buildings with SOLID WALLS instead of MASSIVE AMOUNT OF WINDOWS the map is also winnable and is easy. If the building does have massive amount of windows, it's a hard map. 3. If a map has high rooftops (can't see the square right under you when you go to the edge) map is a medium difficulty map because this essentially makes the rooftop useless. The map may have low rooftops nearby but usually they are too far for you to reach without fighting several squads of aliens. 4. If a map has no buildings, it's a hard map, such as cemeteries, outdoors, construction sites, and bridges. Very good chance you will lose in this map and a damn right guarantee to suffer heavy losses if you do manage to win. Having said that, I do win these maps more often than not however, I always have 1-2 casualties unless I am very lucky. 5. If the map has a train, it is downright #%*@#ing impossible and you should swear out loud many, many times and restart. I'm talking about the train yard with the thousand trains and the train station with the monorail or sky train or whatever it is. God damn I hate those two maps so *$#@ing much. There is one train map that is medium difficulty. Basically the map is divided in 2, one high ground where you start with a building, and the other lower ground. That one is ok, unless for some reason one group of aliens spawn on top of the building instead of inside, then you are screwed. 2.0 Classes 2.1 Sniper The most important class. He is your salvation. He is your god! He is the single most important person in the game! If he dies, restart! Unless of course, you've reached one of the game ending strategies, but seriously, squadsight snipers are the only way you will survive until you reach said strategies. 4 missions and 8 kills will get you squadsight. You need a squadsight sniper by the end of the 1st month, or at the very least, end of the 1st mission in the 2nd month. Here is the recommended build 1. Headshot - Spam this. If a enemy has 4 or more hp, headshot because sniper rifle shots often only do 3 damage. 2. Squadsight - If you think snapshot snipers are even remotely viable, go back to normal difficulty. Impossible is not for you because in impossible difficulty, even when you play like a badass power gamer you have a very good chance of losing, so severely gimping yourself by not taking this ability means this difficulty is not for you. 3.Damn Good Ground - Gunslinger is good. It basically turns your pistol into an assault rifle. Ultimately damn good ground is better for the following reasons. a. End-game archangel armor snipers are game enders, and Damn Good Ground benefits these snipers immensely. b. Early-Game grenades and pistols are more than sufficient. If an enemy survives an attack from your soldiers, he will only have 1-2 hp left. c. After early game snipers rarely get into close range combat. They should be at the corner of the map (literally) or on top of a cliff or rooftop. 4. Disabling Shot - Battle Scanner effectively lets you scout out your landing zone so you can rocket an unsuspecting squad of aliens, wipe em out, and let your snipers snipe away without any fear of enemies closing in. Disabling shot however, lets you capture aliens more easily AND they STOP SECTOPOD OVERWATCH. In fact, THEY DISABLE A SECTOPOD FOR AN ENTIRE TURN, and let me tell you about sectopods, in impossible difficulty these guys can withstand 2-3 turns of full barrages from your entire 6 man squad and 2 shot everyone. I seriously get this ability just for sectopods. 5. Opportunist - Opportunist is amazing, basically makes your overwatch shot a free shot against an alien without cover! No overwatch penalties, and the ability to crit too! Executioner on the other hand is just horrible. If an enemy is less than 50% health, a sniper can kill him without executioner. 6. Low Profile - Amazing. Allows you to go to the edge of a rooftop and hunker down. Also makes snipers the best mimetic skin users 7. Double Tap - In my impossible ironman experience, I never found in the zone remotely useful. It is only useful if you have a heavy that rockets at least 3 aliens at once and the aliens don't have massive amounts of hp. Your biggest problems end-game are heavy mutons and sectopods and even with double tap these guys are hard to bring down. In the zone-ing these guys is a pipe dream. All other aliens should be a joke at this point so definitely double tap. Generally I start training my 2nd squadsight sniper after I get squadsize one. Never have more than 1 sniper in training in your squad unless it's a small UFO crash because the risk is not worth it. 2.2 Heavy Heavies are what gets you through the 1st month. After the 1st month they become less and less useful as enemies with higher hps start appearing. They are more useful than assaults and supports but unless you're going the "carpet bomb" end game strategy, don't bother leveling this guy up. In my opinion heavies peak at squaddie rank. 1. Fire Rocket - The best abilities heavies have. Your saving grace of the 1st month. 2. Bullet Swarm - This lets you shoot then hunker down, basically allowing you to shoot once every turn without any penalties or drawbacks. Holo-targeting boosts your other squad member's shots but bulletswarm's double shot boosts your hit chance from 67% to 89% or 47% to 72% mathematically speaking. 3. Early Game, Shredder Rocket. Late Game, Suppression - Suppression is only useful if you have at least 2 soldiers who have it AND the ammo conservation foundry upgrade. Without the foundry upgrade you simply will have too much ammo troubles to use this. I get shredders because I don't use heavies past the first few months. 4. Heat Ammo - Heat Ammo lets you 1 shot those god damn annoying seekers. God I hate seekers. Rapid Reaction is horrible. Heavies have horrid accuracy, and with the overwatch penalty, it's a miracle if they land a hit. Heat ammo also lets you do more damage with rockets and grenades against the more serious threats such as sectopods, mechtoids, and cyberdiscs. 5. Danger Zone - No contest. If you ever see the massive aoe of a heavy's rocket with danger zone, you'll agree with me. With tactical rigging, you have plenty of grenades anyways and even if you don't, danger zone will let you hit 1 more alien with the rocket, which is definately better than a grenade. Also, danger zone allows you to hit aliens that are on the ground when you shoot a rocket above them, allowing your heavies to launch rockets and flying floaters or from the middle of a rooftop wihtout going to the edge. 6. Will to Survive - Drones will do 0 damage to you. Not a bad ability but is rendered moot against the aliens you fight when you get this. Don't ever use strategies that rely on your soldiers to take damage. 7. Rocketeer - Additional rocket = additional long range cover blaster. Also, 2 rockets do more damage than 1 beefed up rocket. 2.3 Assault Fodder class. After much experience with this class, I am deeming them fodder. While an assault with lightning reflexes is great to have, and I love watching an assault go all rambo and slaughtering aliens with his shotgun, in the end, they are not powerful enough to be essential. You can make do without these guys. Shotgun is too risky because you will almost always trigger an additional group, where as a assault rifle makes you barely better than a rookie. Also, an assault needs to be at least a captain to be a force to be reckoned with. Assault Rifle v.s. Shotgun - Assault Rifle in the 1st month, Shotgun from the 2nd month, and whichever does more damage based on your weapon research. Although it is nice to see an assault run up and slaughter a mind melding sectoid, assaults almost always will trigger an additional squad. After tactical rigging however, grenades will become your "long" range attack option so shotguns are better then. 1. Run & Gun - This makes the assault the "close range sniper" because he can run a long way to blast enemies point blank, but once again, this will almost always trigger more groups so best to not use it until you wipe out at least half the aliens on the map. 2. Aggression - On normal, you could Run & Gun behind low cover and Tactical Sense can save you from the alien group you just triggered. On Impossible, not a chance. Besides this also boosts your assault rifle crit chance, making it on par with your shotgun's critical chance. 3. Lightning Reflexes - Unlike you, enemy's overwatch shots have a very good chance to hit. This is the only reliable way of canceling enemy overwatch shots in short of killing them, allowing you to move your troops up to grenade the enemy. Close and personal would be good if and only if it worked with Run & Gun, but it doesn't, so it's crap. 4. Rapid Fire - Hands down, no contest. Doubles your damage output, and you can use it after you move or Run & Gun. Flush isn't bad, it's main use is when an alien is in full cover, you put your entire squad on overwatch and flush him. It's just that Flush can't compete with rapid fire. 5.Bring Em On - Rarely would an enemy get within 4 tiles of you. Almost always it'll be you who approaches the aliens at that close range. Bring Em On synergizes well with your crazy high shotgun crit rate and your crit rate boosting abilities. 6. Extra Conditioning - Don't let this fool you, this still does not make this guy tanky enough to tank more than 1 hit. 7. Killer Instinct - Resilience will now make your assault tanky enough to take more than 1 hit, but with killer instinct, rapid fire, Run & Gun, Aggression, Bring Em On and Lightning reflexes, this guy becomes a killing machine. So what do you want? Killing Machine or 2 hit tanker? You need the 50% from Killer Instinct if you want to crit any of the robotic aliens, which make up most of your late game experience. 2.4 Support 2nd Fodder class. More fodder than assaults. In fact, these guys are literally marginally better than rookies. I throw these guys away like trash. If someone has to take a bullet, it's this guy. Check the "fodder" strategy on how to properly use these guys. 1. Smoke Grenade - Basically allows your entire team a free shot at the enemy, provided that all your soldiers are behind full cover. Check early game strategies for more detail. 2. Sprinter - Overwatch shots are a hail mary. They almost never ever hit so covering fire is out. Sprinter lets this guy flank and scout better. 3. Smoke and Mirrors - I don't use medkits. They take up valuable inventory slots which are better used for grenades, scopes, or chitin plating. Smoke and Mirrors don't take up inventory slots. Also, if 1 smoke grenade = 1 free shot for each squad member, 3 smoke grenades = 3 free shots for each squad member. Having said that, if you are using lots of MECs, get field medic because smoke grenades won't save your MECs from damage reliably enough. 4. Rifle Suppression - Don't get revive unless you have secondary heart on all your squad members because your troops die more often than getting wounded. That and the will loss makes this not viable. On the other hand, colonel assaults with secondary heart will make revive amazing as half their hp is more than what a medkit can heal, and this allows you to send in your assaults in with reckless abandon. 5. Dense Smoke - No contest. Full cover when in no cover? Hunkered down cover when you're just shooting? Combat Drugs is absolutely pathetic. You should have no will troubles at this point in the game with the officer training school upgrade "lead by example." Also, in impossible difficulty there is just no way you can resist a mind control attempt. The 10% crit rate bonus is a joke. 6. Deep Pockets - Makes the support the ideal arc thrower user 7. Sentinel - Again, I don't use medkits so sentinel. Don't expect sentinel to do anything because like I said overwatch shots are hail maries, unless of course, it's from a sniper. I never got a support to this level in all of my impossible playthroughs. 2.5 MEC Trooper Body Shield - Best ability. It's nothing amazing but the rest of the abilities are worse. Distortion field - The best way to use it is to put your MEC out of line of sight but next to a soldier in full cover but a 10 defense increase won't save you so it's still better to hunker your soldier down than rely on this ability. Platform Stability - In order to utilize Platform Stability you need to take a hit first so this is not optimal. Shock-Absorbent Armor - This ability is just bad. You should never, ever, ever get hit by a melee alien, ever. I can't remember the last time even a chryssalid landed a hit on me. I usually turn my supports into MECs because snipers and heavies are just too precious to turn into MECs. I turn snipers into MECs if I have like 3 of em in my barracks. I don't need that many snipers, and squaddie snipers are deadweight. 1. Collateral Damage - Amazing! Blows up cover AND CARS!!! Too many times I blew up cars with 2 grenades, killing 6 hp thin men with 12 damage but not anymore with this guy. Also blowing up cover makes focus fire strategy amazing, and is practically a guaranteed sniper shot. Only problem is it's insane ammo consumption. You won't pull it off more than once in a fight. Good thing MECs have a ton of abilities other than their main weapon. 2. Advanced Fire Control - Automated Threat Assessment is just bad. The only time I found it useful is when my body shield kinetic strike MEC fell a few tiles short of an alien in full cover. A shot would definitely miss so I use this to increase my chance of not getting shot, but then a MEC should have other options like flamethrower, grenade, etc so never ever get Automated Threat Assessment. Also, Automated Threat Assessment ends when the MEC takes an overwatch shot. 3. Vital Point Targeting - Let's see... 2 more damage on everything, or 2 less damage on the 2nd shot you receive. I generally don't get hit more than once so you shouldn't either. That and the 2 damage can be the difference between 1 shot kill and 2 shot kill. 4. Jet Boot Module - This ability lets your MEC get on top of rooftops. One for all turns your MEC into a bullet magnet who can't use arm weapons. I think this is a no brainer. 5. Expanded Storage - Restorative Mist heals 6, 8 if you have a medal, and is AOE, so there is no benefit of repair servos here. Grenade Launcher users would also prefer an extra grenade over 6hp. 6. Overdrive - I rarely use this. MECs move and shoot/use ability. If my MEC uses overdrive, that means my team failed to kill the opposing alien squad and they shoot my MEC, who gets damaged. On my next turn, snipers kill the surviving alien without my MEC. So if you're thinking of turning a sniper into a MEC to take advantage of this ability, don't. Only turn snipers into MECs when you have lots of snipers or going the Sniper MEC Squad end game strategy. 7. Reactive Targeting Sensors - I usually go 1 MEC or 6 MECs. If I go 1 MEC, I can afford the MEC-3 which makes Absorption Fields useless. If I go 6 MECs, I'm doing the Sniper MEC Squad in which case Reactive Targeting Sensors is much, much better. If you are however, ridiculously short on Meld due to heavy genetic mod usage, then get Absorption Field MEC-1s ot MEC-2s. MEC-1 Early Game Flamethrower - Get this for your mid game MEC. Kinetic strike requires foundry upgrades to be superior to the flamethrower. Having said that, end-game make your new MECs kinetic strike even if you're going the carpet bomb strategy. You can get Kinetic Strike early game and still do fine if you don't plan on switching MECs, but flamethrowers are much better and safer earlygame because a. At melee range, no alien can survive your minigun blast so the extra damage from kinetic strike is pointless b. Flamethrowers have longer range and AoE, allowing you to approach and kill 2/3 aliens in a group. c. Like shotguns, getting in close range with for kinetic strike will almost always trigger more aliens. The only thing Kinetic Strike does better than flamethrowers early game is killing Chryssalids and zombies. MEC-2 Grenade Launcher - Like I said I don't use medkits. If I don't think I can kill the alien group after a collateral damage, I use grenade launcher and destroy the cover from afar. My MEC never, ever gets hit if I can help it. Having said that if you're going Sniper MEC Squad end game strategy, then get restorative mists. Strategy is Move then Shoot, get shot at and shoot back, then double shoot, all with 105 aim, and heal up afterwards. MEC-3 Proximity Mines - Both suck but at least this can be combo'd with grenades from other MECs or heavies. Only robotic enemy I have trouble with is the Sectopod but I can't get in range to use Electro Pulse without getting hit by an overwatch shot so the point is moot. You can follow up a disable shot or lightning relfex with Electro Pulse but I rather double shoot ro kill it rather than run up and use this pitiful ability. 3.0 Early Game (1st month) Strategies Your options are very, very limited and as such these strategies are not anything special however, utilizing these strategies is your best chance at making it to the 2nd month. 3.1 Moving Hunker It's obvious what this is but it's good to have a word for it so I don't have to describe it every time. You just move your entire team from heavy cover to heavy cover and hunker down. Important! Your entire team must hunker or do an action. Never hunker if one of your squad members does an action because aliens will target him. You're only strong as your weakest link. The exception to this rule is that if the guy who did the action is at the back of your squad and out of range. Then your aliens will not advance into range due to your wall of hunkering soldiers. 3.2 Mind Meld Exploitation Basically you trigger a group, do the moving hunker, and next turn grenade/rocket the mind melder. If the group of aliens is 3, pray to god your other squad members kill him or he doesn't kill you on his turn. It's not as bad as it sounds though, often times they run away out of your sight and come back a few turns later. Do not underestimate this strategy, as this strategy is your salvation in the 1st month when you trigger multiple groups at once. I once had a heavy kill 8 sectoids at once with this strategy when I accidentally triggered 3 groups at the same time. I generally always use this strategy against every group I encounter because if a sectoid mind melds, then 2 grenades will guarantee 2 kills. That and you get weapon fragments. 3.3 Focus Fire Have your entire team shoot an alien in low or no cover. More often than not this will kill him. Combo with moving hunker. Only use this in 4 vs 1 scenarios or 4 vs 2. 4 vs 2 is risky because if you fail to kill, you might lose the map. Don't use this against an alien in full cover unless on a rooftop. 3.4 Shoot and Smoke Basically you have your entire team behind full cover, shoot, then pop a smoke grenade. Nothing fancy. I use this if I'm out of rockets and grenades. 3.5 Bullet swarm and hunker Usually your second long range combat option as your heavy will get more kills than your sniper. Just move your heavy to full cover and hunker, shoot and hunker x3, then move out of line of sight to reload. Hopefully with all your grenade and rockets, you only need to use this strategy against only 1 group of sectoids. 3.6 Surprise! Best used on maps with buildings without massive number of windows. Basically have 3 guys hide behind the backdoor, have one soldier trigger the sectoid from the front, and once the sectoids take cover, open the back door and blast them. They should be flanked. If not, move and grenade them, or proceed to use Mind Meld Exploitation before opening the backdoor. Be very careful not to trigger a 2nd group. If you think you will, don't use this strategy. 3.7 Batman Just like Surprise but instead of the backdoor it's rooftop. Have one guy drop down on the one side of the rooftop and have the rest drop right behind activated sectoids. If you combo with Mind Meld Exploitation, then you can drop right next to the mind melder and kill 2 sectoids with 1 shot and have the rest grenade or focus fire the sole survivor. Sometimes you don't even need to drop down as you can get a flanking angle while still on the rooftop. 3.8 Overwatch Camping Basically you get your team behind full cover and overwatch for 30 turns. 40 if you have to. I do this when I am in some horrible map like the cemetery grand. If no patrol wanders in for 30 turns, I advance to the next line of heavy covers and overwatch for another 30 turns. The main purpose of this strategy is to force the enemy to fight you in lower cover while you're in high cover while at the same time not triggering more than 1 group at a time. IMPORTANT! I know some people think triggering a group with 1 soldier, and having him run back into an overwatch trap is a good idea but the thing is, IT'S NOT! It used to be awesome in enemy unknown but in enemy within, AI got smarter or something because the aliens are omniscient and knows exactly how to get into cover right at the edge of your vision, thus not triggering overwatch, and splatter your soldiers all over the pavement. I never got the overwatch trap to work in enemy within and even if I did, overwatch shots are hail maries. If 4 overwatch shots miss when a patrol rolls right into my face, what chance does overwatch traps have? 3.9 Fall Back You move your entire squad back into another row of full cover. It's ok to dash in this situation because you have already cleared the area behind you and the enemy in turn has to dash to you in order to get in range. I generally spam hunker until the aliens show up unless I am absolutely sure the aliens can't move into cover at the edge of my vision. 3.10 Fodder Move your support or assault to low cover and fire or throw a grenade, don't hunker. In impossible difficulty the AI is smart and will kill your sniper first, no matter what. If you do this though they'll kill your support or assault instead assuming your sniper is in full cover. I do this when my sniper misses a critical shot or I am out of smoke grenades and need to focus fire against 2 or 3 aliens. 4.0 Mid Game Strategies (2nd month+) These strategies should keep you alive until you reach an end game strategy. 4.1 Hunker and Snipe Have your squadsight sniper in the back, move your squad forward behind full cover and hunker. Your enemies will not advance because of your wall of hunkering soldiers, they will never land a hit on your hunkering soldiers, and your sniper will kill all of them afar. This is your only way of beating long narrow maps. In fact this strategy makes long narrow maps easier than the ones with rooftops. Be careful not to get flanked though, and make sure the heavy cover is indestructible. You really only need 1 spotter, the rest is just to discourage the enemy from flanking. If you use this strategy in conjunction with the others, there is no mission you can't beat. 4.2 Lobbing ungodly amount of grenades. My favorite mid game strategy. Requires Asia start. In my 1st month I rush experimental warfare, build a foundry and upgrade tactical rigging. Then I lob an ungodly amount of grenades against the aliens. Any survivors (if there are any) are then slaughtered through flanking, shotgun assaults, or with the Hunker and Snipe strategy. This strategy is awesome! It practically guarantees I'll survive until I get my alloy SHIVs. Also, it makes rookies not useless! I can beat every abduction mission on the 2nd month with 1 sniper and the rest rookies. Needless to say this strategy will make training additional squadsight snipers a breeze. I can get 3 squadsight snipers by the end of the 2nd month if I wanted to. Also, grenades are reliable damage. That means RNGESUS can't screw me over. Once mutons appear though, this strategy starts to fall flat and you should switch your inventory to scopes and nano-fiber vests, or get alloy SHIVs. You can see that this strategy transitions well to late game because tactical rigging is never useless. 4.3 Mimetic Skin Abuse I don't like this strategy. People go on and on about how broken mimetic skin is but in truth, it's not. The gist of the strategy is you have one mimetic skin scout find a group of enemies and have squadsight snipers kill them from afar. Aliens will just dance around and die. There are a number of problems with this strategy. a. You need to autopsy a seeker to get it, so you're not gonna get stronger until the middle of the 2nd month. Good luck surviving thin men, floaters, and seekers, especially if you trigger more than 1 group and failed to get the officer training school in the 1st month. b. Aliens are close to you at the start of mission. This strategy won't save you from the 1-2 alien groups that wander into you. Good luck fending off 6 thin men/floaters/seekers especially since the mimetic skin soldier can't join the fight due to the fact of him being right next to a group of aliens. c. Because you invested your money into mimetic skin, you don't have tactical rigging, MECs, or SHIVs so your options are limited to that of the 1st month except mind melding exploitation is no longer available due to the absence of sectoids. Good luck fending off 6 thin men/floaters/seekers d. Only works on long narrow maps, which you can beat with Hunker and Snipe. Small maps everyone will wander into you before you can take out even one group with this strategy. Remember, 1 sniper will take forever to kill anything by himself because of the misses he makes and the inability to reliably one shot the enemies. e. Can't beat UFO landings. Every time I rely on this strategy, I get raped by UFO landings. First I find a cyberdisc on that small UFO map and shoot a drone. The cyberdisc however amazingly knows where I am and hovers to me. Overwatch shots from the rest of my squad barely does anything, and then the cyberdisc kills my sniper. If miraculously my sniper didn't die, a mechtoid then wanders into my group. And again, if miraculously I kill the cyberdisc, a second cyberdisc wanders into my group and then it's over. If I abort the mission to save my sniper, my mimetic skin scout is gone, and having spent so much money and meld on the scout, it's pretty much game over. This happened to me more than 3 times at which point I gave up trying to use this strategy. Don't get me wrong though, mimetic skin is powerful late game, after you get a few colonel snipers. I beat the final mission the first time with this strategy. Mimetic Skin is amazing support skill as it lets you setup your heavies and snipers before engaging, and get your assaults within melee range, but just don't rely solely on it. On a sidenote, think twice before using this against sectopods. Sectopods can see invisible units and although they can't attack the unit directly, they can initiate their aoe attack, forcing you to expose your out of position soldier and frantically try to save him. 4.4 Flaming MECs Get a flamethrower MEC, preferably support. You will throw this MEC away later unless doing the carpet bomb strategy. MECs can 1 shot floaters and thin men. MECs can blow cover away infinitely (only once per fight though because they don't have ammo). MECs can blow up cars so that you can use your grenades and rockets on the aliens not next to cars. Flamethrowers are basically close range rockets, but they have enough range that you don't risk triggering additional groups of aliens. A viable strategy, not as good as lobbing an ungodly amount of grenades, but I use this strategy just for fun. Much more viable than mimetic skin abuse because MECs are cheap. If you lose one, doesn't matter, you can get another one cheaply. An advantage over lobbing an ungodly amount of grenades is that you can afford officer training school and cybernetics lab on the first month, and without Asia start, where as trying to get both officer training school and tactical rigging is very hard. 4.5 Suppression March This strategy won't win you the mid game, I never use it, but it is a strategy you can use if you want. Basically at long ranges, you suppress an alien and have your squad perform the moving hunker across low cover so they may get in range for grenades, flanks, run & gun, etc, or just employ the focus fire strategy. The problem with this strategy is that you can only suppress aliens equal to the number of suppressors you have and you can't use this more than once per fight due to the high ammo consumption suppression abilities have. 5.0 Game Ending Strategies Basically once you get one of these strategies, game is over. Not even 5 sectopods can stop you, unless you are extremely careless or unlucky. 5.1 Unending SHIV Onslaught Easiest and best end-game strategy as it is completely soldier independent. Basically if you take this route, the game ends once you kill your first drone, which is month 4. There is nothing in the game you cannot kill with 6 alloy SHIVs with sentinel drones. 6 Shivs blast and kill one group, wait a few turns to heal up, and repeat. It only takes 2 SHIV shots to kill anything other than sectopods, so at best 1 alien will survive your first attack, and against sectopods, just have 3 SHIVs suppress it. That's 90% aim reduction and SHIVs have 10 defense. 3 SHIVs shoot, 3 suppress, it's over. Sectopod can't do anything. You don't need to have SHIV laser or SHIV plasma researched for this to be a game ending strategy because at that point in the game, you don't need them, and I'm pretty sure you are not a complete retard who would not focus his research towards SHIV weaponry after you get sentinel drones. You don't even have to go pure SHIVs. My setup is usually 2 snipers, and 4 SHIVs who go up and melee the enemy. Hover SHIVs are not a priority as you can beat the game with only Alloy SHIVs. Hover SHIVs take a while to research and require an insane amount of weapon fragments, and Plasma Weaponry gives way more benefits than hover SHIVs do. Be sure you get your 1st drone corpse in month 4 otherwise the game will become significantly more difficult. Best thing about this strategy is that there is lots of room for mistakes! You can take hits without consequences and if you do fail a mission and get squad wiped, no problem! It only takes 4 days to rebuild your entire squad. On a side note, laser alloy SHIVs will one shot everything weaker than cyberdiscs which makes your game too easy until you reach plasma weapons. Proper SHIV strategy 1. Normal Alloy SHIVs Just run up and melee them (be sure to be 1 space apart from the target otherwise they get half cover bonus from your shiv!). Alloy SHIVs can one shot the target almost all the time if they're flanked but because their aim is the same as rookies, try to melee. Unlike rookies however, these guys can take a massive beating before dying and their damage output is phenomenal. 2. Laser and Plasma Alloy SHIVs Meleeing is no long required, just flank em though being close is always better. Move your SHIVs parallel to the enemy and attack. 3. Hover SHIVs. In addition to everything above, you can just fly to the highest possible elevation and attack. That's 95aim + 20 = 115 aim though flanking will net you significant bonus to critical chance. 5.2 Mimetic Snipers 6 archangel plasma colonel double tap snipers with mimetic skin. One sniper scouts with low profile, the other 5 hide, when enemy is found, BAM 6 double tap critical hits with plasma. Or just go into the air and stay there forever, using only 1 fuel. Rinse and repeat. 6 snipers is overkill but hey, why not? The general strategy towards achieving this is you go the lobbing ungodly amount of grenades mid game strategy, level up as many snipers as you can (exalt missions help a LOT), and once you get a healthy 2-3 squadsight snipers, give mimetic skin to your squaddie snipers and use the mimetic skin abuse strategy. Your squaddie sniper will eventually have been in enough missions to get squadsight, at which point you get another squaddie sniper with mimetic skin as a scout. Keep doing this until you have 6 squadsight mimetic skin snipers and eventually they'll all be colonel. In my experience game effectively ends around month 4-5 when I get 4-6 squadsight snipers thanks to EXALT missions and tactical rigging. 5.3 Sniper MEC Squad You 6 MECs who were formerly colonel snipers. Ultimate move and shoot squad. You move, you shoot, and then you heal up with mists. Kind of pointless because 6 Colonel Snipers will already win the game for you, and 3 snipers > 3 MECs, so there's no point in converting your colonel snipers to MECs unless you have 4 or more, and even then, MEC-3s are insanely expensive although MEC-1 is all you really need because MEC-3 does not increase damage, only HP. Get 6 MEC-1s first, then 6 MEC-2s, then finally 6 MEC-3s. Getting the MEC-1s first is highest priority, then getting as much healing is 2nd priority. MEC-3's abilities are kind of sub-par so there's really no reason to get it unless as a status symbol. If I do go this strategy again, I will probably stick to only 4 MECs and keep 2 snipers because snipers can shoot twice without moving and colonel sniper MECs are better than SHIVs. Also 1 or 2 disabling shots against Sectopods would've made this run a lot easier, and I was always 1 or 2 shots away from wiping out a group of heavy mutons, and 2 snipers will give me 2 more shots. 5.4 Carpet Bomb 6 heavies and MECs. Ideally it'll all be 5 heavies and 1 MEC but MECs don't need to be colonel. They just need the MEC-3 Paladin so they are expensive substitutes. Basically you complete every mission by using an ungodly amount of grenades and rockets, supported by proximity mines. Close to mid range I use flamethrowers, kinetic strike, the heavies' grenades, or just blast them if they'll die to normal weapons. Long range I use rockets and MEC's grenades/mines. MEC-3 Paladins are literally mobile artillery, they just need to travel in groups of 2 or more to use proximity mines. Problem with this build though is end-game you need blaster launchers, and battleships are a pain in the ass to shoot down. In fact in most of my playthroughs I let the battleships destroy my satellites and just put up a new one if they do. I always keep a spare and they destroy a satellite like once every 3 months. Mimetic skin is optional and helps getting your heavies into position before engaging. 5.5 Assault Rain 6 lieutenant or higher assaults with mimetic skin and archangel armor OR titan armor with Muscle Fiber Density. Basically you mimetic skin your team as close as possible to the enemy, then the next turn, Run & Gun and rapid fire right into their faces. I personally don't like this strategy because it's really hard to get 6 lieutenant assaults. Unlike snipers they have a high mortality rate and unlike SHIVs, are not expendable. This also means if you make a mistake and you lose 2-3 assaults in a mission, you are screwed and either switch to the Unending SHIV Onslaught or lose the game. 5.6 Mix of Everything Just like the title says. 6 colonel w.e and maybe with some SHIVs, you can beat the game. This strategy is not amazing or special but it's proof that you can play this game anyway you want and win. This strategy is more difficult than the others because it has nothing really going for it therefore you can't just bulldoze your way through the game. If you fail you can always switch to one of the above strategies. 6.0 Walkthrough This walkthrough will be focused on going the lobbing an ungodly amount of grenades mid game strategy and the Unending SHIV Onslaught end game strategy as this route is the easiest. If you want to try something fancy or fun like using MECs, I will make a few notes throughout the walkthrough telling you to adjust accordingly. Also, I do not attempt the alien base assault until late game as I like to take my time, and it's easier because every dollar and research time spent on the alien assault stuff could be spent on combat related upgrades. I also do not bother myself with meld as SHIVs are superior to all forms of meld technology and I am tight on funds. Short Version of the walkthrough 1st month 1. Perform the strategies listed in section 3.0 in the guide to win your fights. 2. Get Scientists 1st, engineer 2nd. This month is the only month where you can attempt to get scientists as a reward. 3. Research weapon fragments, experimental warefare, alien materials, carapace armor 4. Build a foundry and upgrade tactical rigging 5. Make sure to have phoenix cannons on both of your interceptors (My squad composition is 1 sniper, 1 heavy, and 2 miscellaneous.) 2nd month 1. Lob an ungodly amount of grenades at the enemies and kill the survivors off with your squadsight sniper. You may use this opportunity to train more squadsight snipers. This strategy should carry you all the way to month 4. 2. Build 3 satellites and 1 satellite uplink. Prepare the base for a workshop (to be constructed next month). 3. Build officer training school and get the squad size upgrades and rapid recovery a.s.a.p. The rest are luxury though Lead by Example is more important than the others. Iron will is too expensive for now and will is not an issue in this game. I have beaten the game without iron will. 4. Research beam weapons. If you didn't get the 4 scientists at month 1, you will still be researching carapace armor. See why scientists 1st is important? 3rd month 1. Build 3 satellites and a workshop, then a satellite uplink 2. After EXALT does it's thing build 3 alloy SHIVs 3. Alloy SHIVs make exalt missions a cakewalk, and slowly transform your squad to 4 SHIVs and 2 Snipers or 3 SHIVs, 2 Snipers, and 1 assault if you have a high ranking assault. If you don't, don't bother. 4. Research heavy lasers before precision lasers. Laser SHIVs will one shot everything weaker than cyberdiscs. 4th month 1. Build however many satellites you need to cover the rest of your countries +1 (spare in case a battleship shoots one down), a workshop, then a satellite uplink. 2. Build alien containment facility and capture a muton so you can start your plasma research. It HAS to be a muton because they skip light plasma rifle and halve your plasma research time. It's ok if you fail to capture a muton this month. Laser SHIVs are really powerful. 3. Build 4-6 laboratories. Plasma weapons will now only take a week to research. 4. IMPORTANT! Make sure you get a drone autopsy this month! There is nothing that you can't kill with sentinel drone SHIVs. Game effectively ends here because sentinel drone SHIVs are insanely powerful. 5th month+ 1. Continue plasma research, you can attempt alien base assault this month, though I like to wait until I have plasma alloy SHIVs and 2 plasma sniper rifles. 2. Once you get 2 snipers with plasma rifles and 4 plasma alloy SHIVs (with maybe 2-3 more for backup), you win the game! 3. Research towards new fighter craft, EMP cannon, and archangel armor, and be sure to get all the foundry upgrades related to SHIVs! 6.1 1st Month This is the hardest part of the game. On a side note, I usually make it past the 1st month about 70% of the time. It's not that hard, just a lot more dependence on luck than the other months. Start in Asia. You don't need Europe's bonus until month 5, You can make do without South America's bonus (although it is nice to have), you save more money starting in Asia than in Africa because you'll be spending all of your money not spent on satellites on foundry upgrades and the officer training school, and north america bonus is a joke. I generally only try to save U.S. for the money in north america. Restart the 1st mission until you get an easy map. Then hope to god your 1st abduction mission is not a hard map. Try your best complete the 1st month before you restart if you fail. You need the practice. Just do the strategies I mentioned and you should be fine after 1-3 attempts. As I have said, I have about 70% success rate in the 1st month, and 90% game success rate after that. Always border skim. I generally border skim behind the building, blasting any aliens I encounter with explosives, and then go up to the rooftop. General Strategy There are 4 groups of sectoids. Either 3:3:3:3(very difficult) or 3:3:2:2(difficult). Fact: You can wipe out a group of sectoids with 1 rocket or 2 grenades Fact: You have 4 grenades and 1 rocket, so you should be able to wipe out 3 groups with your explosives and somehow kill the last group. Do NOT underestimate the last group. 3 sectoids at long range wiped out my entire squad several times. You just cannot win a long range fight, heavy cover vs heavy cover, with no way of flanking them. In these cases refer to the fall back, smoke and shoot, and focus fire strategies Don't be afraid to just fire and hope for a miracle. XCOM is very luck based and you might get lucky. I just do my best and more often than not I complete all 3 missions with my sniper and heavy at corporal or sergeant rank. I usually have 2-3 casualties however. Engineers v.s. Scientists v.s. Money v.s. Sergeant Recruit One of the abduction missions have to be the 4 engineers. If you get the engineers 1st, then you can fail the 2nd abduction mission and still be somewhat successful. If you go scientists first, you can get carapace armor by middle of month 2, and alloy SHIVs before the 1st terror mission. If you want both tactical rigging and officer training school, you need 1 engineer, 1 $200, and a soldier with sergeant rank (usually your heavy as his rockets and grenades will net him the most kills every mission). I generally never get the sergeant, even if it's a sniper, because I need the money and engineers more. I generally pick scientists 1st, engineers 2nd because 4 scientists effectively halves all your research time, and the 1st month is the only month you can attempt to get 4 scientists as a reward. Interceptors Get Phoenix cannons at the end of the month. An interceptor with phoenix cannon can take down all small, medium, and large scouts solo. Anything bigger and you need to do some heavy investment into interceptors, which you can't do because you're tight on funds just getting the satellites up. Compare the cost of outfitting interceptors will all those fancy temporary boosts or... having a satellite in reserve. Outfitting both of your interceptors with phoenix cannons is more important than officer training school otherwise you are leaving the success of the 2nd month to luck as you have a good chance of losing a fight against a medium scout with avalanche missiles. Grey Market SELL SELL SELL! I sell everything, and I mean EVERYTHING except weapon fragments and 10 alloys. When I do the alien nav research, I am well into month 5 and get a ton of them after 1 UFO crash/landing. General rule of thumb is sell everything except weapon fragments, 1 of each corpse you didn't autopsy, and 3 sectoid corpses for the alien biology research (I don't do this one until I finish laser weaponry). Don't sell alien alloys if you can help it unless you're not going alloy shivs. Keep selling elerium until you reach plasma research. I generally stop selling elerium when I can afford to or when I finish my laser research. Pick a mid-game strategy You have 4 choices here, foundry, officer training school, cybernetics lab, and genetics lab. Refer to the above strategy sections on which to choose. I choose foundry for tactical rigging. I generally can't afford to build officer training school this month but that's fine. I can beat the 2nd month with 3 rookies and 1 sniper with tactical rigging. If you do decide to go mimetic skin, get officer training school first. You can't get mimetic skin until after you kill a seeker anyway. A note on officer training school, you only need the squad size upgrades and rapid recovery. The rest is just luxury. I get squad size upgrades and rapid recovery as soon as possible, then lead by example, wet work, and finally iron will. Will is simply never an issue in impossible difficulty because lead by example will solve all of your panic problems, and there is no way you will resist mind control so no point in attempting to beef up your will. Research 1. Weapon Fragments - Scope on squadsight sniper is essential 2. Experimental Warfare - Only if you're going lobbying an ungodly amount of grenades strategy. Otherwise skip or get Meld Recombination. You get 40 meld after you complete this so it's a guarantee that you can get at least 1 MEC in the 1st month. In fact you can do Meld Recombination before Weapon Fragments if you're set on going MECs. 3. Alien Materials - Required for Carapace Armor 4. Carapace Armor - The only armor you'll have for a long, long time, as you really need to start researching weapons after this. Also you get alloy SHIVs, which puts you half way of completing the Unending SHIV Onslaught end game strategy. 5. All laser research, heavy before precision if using SHIVs, otherwise skip heavy lasers. Some people say they skip lasers for light plasma rifles, I say don't. Plasma takes an insane amount of time to complete in impossible (like 3+months), and also requires an insane amount of weapon fragments, which you won't have. Go ahead and skip laser if you want, and when you learn that all of your units do absolute crap damage against the impossible aliens' massive hps, you'll know better next time. I don't buy any laser weapons because EXALT gives a ton of em unless I get 4 scientists in the 1st month. You can't use EXALT laser weapons if you didn't do the weapon research so don't think you can skip lasers for plasma. 6. All plasma research - plasma sniper rifle is just awesome. You only need 2. Get heavy plasma 1st if you are using SHIVs. Council Missions SKIP SKIP SKIP SKIP SKIP or... use them to give 1-2 kills to your sniper and bail. I enable the 2 DLCs so there's less chance of bomb missions. I have successfully completed all of the councel missions in the first 3 months but only with 2-3 heavies and squad size 1. It required complete memorization of the map, rocketing the untriggered spawns, overwatching the thinmen landing spots, and extensive mimetic skin abuse. Hunker and Snipe strategy is hard to pull off because thinmen poisons your hunkering soldiers. 2 poisonings and they are dead, so unless you want to risk your entire playthrough by pulling off these cheap underhanded tactics, then by all means do the council missions but I have beaten impossible ironman many, many times without touching council missions until I get squad size II. Medals Urban Combat Badge - +5 aim against enemies in full cover and give it to your sniper. End of discussion. Defender's Medal - If you're using MECs, get the +2hp heal. Otherwise get the anti-panic and give it to your sniper. International Service Cross - +2 aim, end of discussion. +2 aim is better than +12 will anyday, and who knows? You might get +4 or +6 aim! Council Medal of Honor - +1 Aim and Will for each mission completed with no soldier deaths, up to a maximum of +10. Requires more work than the alternative but who cares. Star of Terra-Entire squad receives +5 Will and +5 Defense in battle. Robotic units receive only the Defense bonus. +5 defense is better than 25% xp gain because one can help you in combat, the other can't. Base Building From left to right: Officer Training School/genetics lab Empty Satellite uplink Access lift Foundry/cybernetics lab Generator Empty Reason for this is layout is that you need a workshop in month 3, and if you don't want to excavate a ton of dirt, you will be building the workshop next to the access lift, which is why you're building the foundry/cybernetics lab next to the access lift for the synergy bonus with workshop. UFO Crash This warrants special discussion because some people like to ignore the small scout in order to bait the medium scout and take it out. I recommend against this because although it will potentially double the money you get from the small scout, the mission is as hard as an abduction mission AND there is a chance the medium UFO will escape before your 2nd interceptor reaches it, ending your impossible ironman playthrough right then and there. It's up to you, because it's only the 1st month you can just keep restarting until you succeed this trick giving you the best start possible, but I warn you, it will require a lot of restarts unless you get really lucky with your maps. Checklist 1. Got 4 scientists 2. Got 4 engineers 3. Got a squadsight sniper 4. Got 2 Phoenix Cannons (don't ignore the importance of phoenix cannons! It's either this or doubling up your interceptors per continent, which is risky and expensive.) 5. Got your midgame strategy ready (tactical rigging) 6.2 2nd Month If you went lobbying an ungodly amount of grenades strategy, this month is a piece of cake. Just watch out for the surviving thin man or floater in the group of 3. Don't be afraid to use 3 or even 4 grenades per group, you got plenty of them. 1 grenade per alien is fine. 1st Terror Mission I sometimes succeed, sometimes fail. Doesn't really matter. This month should be the last month where you lose countries. Mission is not hard. Floaters and chrysalids will kill civilians before your soldiers so you can be much more lenient with your hunkering. My success or failure usually depends on whether or not the chryssalids stay together or completely split up upon being activated. If they go to 3 different parts of the map while I'm fighting floaters, I generally abort after exhausting all of my explosives unless I managed to kill all of the floaters with my explosives. Chryssalids are your main priority, and then it's zombies who's been infected for at least 2 turns. Abduction Missions You will no longer do missions based on rewards. You will do abduction missions to save the continents you want to save. Still, you will need an additional 4 engineers so sacrifice a continent bonus if you have to. Which continents to save: Africa and Europe. Once you max out your satellites, you will be building a ton of laboratories (5-6) and Europe makes it a lot easier. The money bonus Africa gives is very noticeable and money is always an issue. My favorite playthroughs are when I only lose North American and Asian countries. Base Building First buy the satellites! Then make money from a UFO. Then build an Satellite uplink. After that build a power generator and an access lift. Get an officer training school, you really, really need the squad size upgrade. Nothing can stop you if you get squad size II and tactical rigging. That's 11 grenades (one spot is for scope). You should be set until month 4. 6.3 3rd Month This is the month where you start ditching your soldiers for alloy SHIVs. Alloy SHIVs can 1 shot everything weaker than cyberdiscs (which is everthing at this point in the game) and can take a massive beating. 4 alloy SHIVs and 2 snipers will win you the game. EXALT Annoying, yet a blessing in disguise as it allows you to level up a 2nd sniper without any drawbacks (if you didn't start training additional snipers already). Missions are quite easy. Exalt may have massive hp, but they do pathetic damage. They will almost never 1 shot you. Getting data is easier than guarding data because there's only half the EXALT troops in the former, and you can time your comm disruptions really well to completely annihilate everyone without any risk to yourself. If you're doing a guarding the data mission, just overwatch like crazy, 1-2 soldiers will continuously suicide against you. Have your covert operative by a enemy comm at the start because that's when you have the highest chance of being swarmed by EXALT soldiers. A couple of alloy shivs will make things significantly easier as they can just flank and 1shot all of them with crits, and take about 5 shots before dying. Funny thing is lots of the EXALT soldiers just move twice without even shooting! Be sure to check covert operations at least once every 2 weeks. Kill EXALT heavies as quickly as possible, their rockets are devastating. Rest are jokes. I usually have 3 alloy SHIVs by this time and they just annihilate the mission. Base Building. Build 3 satellites. After finishing your 2nd access lift, excavate the both sides, build a workshop under your foundry or cybernetics lab, and build a satellite uplink and additional power generators. You might want to excavate next to the access lift in month 2. Needless to say this will burn most of your funding this month. I usually have enough to build a genetics lab and give mimetic skin to 1 of my units, usually a heavy since they need a full turn to use a rocket. Council Missions I'm comfortable with doing council missions after squad size 2 upgrade. You should be fine with a squad of 6 and one high ranking sniper and heavy, since council missions don't have anyone stronger than a thinman. 6.4 4th Month Base Building Build however many satellites you need to cover the rest of your countries, +1 (spare in case one gets shot down). Build the alien containment facility so you can start your plasma research. Capture and interrogate a muton. Shouldn't be hard at all because your snipers should be really capable now, with medals too! If you have the money, start excavating and building laboratories like mad! Abduction and 2nd Terror IMPORTANT! If you are going the SHIVs endgame strategy, you must complete one mission that has a drone in it! Without sentinel drones, you are going to have to be really be careful about your SHIVs hp. Win the mission with the drone at all costs! 6.5 5th Month Base Building 5-6 laboratories. I fill the entirety of my left side of the base with laboratories. This and muton interrogation will now make plasma research about a week long. If you skipped laser weaponry, you'll still be here, except instead of laser weaponry, you have a light plasma rifle, or pistol if you were dumb enough to research that. You should be fine now if you reached this point. You'll have to screw up big to lose the game. With so many laboratories getting alien base assault should be really quick and you can end the game relatively quickly from there. A note in about base defense, the top 6 soldiers in your barracks list will join you. SHIVs CANNOT JOIN YOU! Keep note of this. I have beaten the alien base assault with 1 colonel sniper, 1 major sniper, and 1 colonel assault only but I would recommend you get a full squad. 7.0 Miscellaneous Tips Abandoning missions Don't be afraid to abandon, as long as you keep your panic level under control. Terror mission with 5 sectopods? BAIL! UFO landing with 5 triggered alien groups? BAIL! Don't abandon too much though, as every failed mission means you get that much less income, which means you won't get stronger, which kind of starts a chain reaction to your downfall. 8.0 Alien Specific Strategies I won't be covering every alien, just the ones that require special attention. 8.1 Seekers The bane of your snipers, and the cause of 99% of your wounded soldiers. If the seekers go invisble, you can find them by combing the map, tile by tile until you find a tile you can't move to. It will be greyed out. That's where the seeker is so grenade it! It will then lose it's invisibility AND it won't be airborn so no -20% aim penalty. Check walls/covers first, if a seeker is next to a wall or cover, you should be able to easily detect it from the borders of your soldier's move action. 8.2 Sectopods The only alien that you can't kill in one turn. What I generally do is I disable shot with one of my snipers (should have 100% chance to hit at this point) then move my SHIVs into position and blast away. Then on my next turn I kill it. In other words, you shouldn't need more than 1 disable shot and 2 turns to kill a sectopod. 8.3 Berserkers Move your SHIVs near the berserkers and kill the mutons. Then with one soldier or SHIV attack the berserker, he will move towards the shooter therefore triggering the sentinel drone reaction shot from the SHIVs you placed next to him, killing him. I hope this guide is helpful, I'll add to it later if I think of new stuff. Oh and some of you may have noticed I call some of my strategies differently than other people, like carpet bomb instead of blaster bomb, well that's because that's what I called those strategies when I came up with them. I know I wasn't the first to come up with them but I'm not changing my habits or terminology just because I wasn't the first. Hidden Section Cheating You can cheat easily by pressing alt-f4 before the end of the alien's turn. So if an alien kills a crucial guy, alt f4 and redo your turn. I don't cheat, but for some people, 1st month is too difficult so perhaps you can cheat through it to make your experience a little more satisfying. Maybe also use it to undo a grievous mistake later in the game like the death of your colonel sniper. Its your single player game so play how you want to but I wanted to beat this game legitly so I did, but I also did 2 cheating runs before I got good enough to beat it legitly.