This game is hardcore. This game takes no prisoners. I don't care if you're playing on Easy or Impossible, this game will still happily turn around when you least expect it and kill you. At least, when you have my apparently low grasp of tactics and basic battle strategy. I've finished the game at least 5 times and it was never easy and it never felt like the game was playing fair with me, so I never played fair with it. With this guide, I endeavour to enlighten anyone out there who, like me, gets a real kick out of this game despite being absolutely horrendous at it. So anyone on here hoping for some pro-tips for their 3rd classic ironman playthrough or some sweet long war tips, get the hell out: this walkthrough is NOT for you, it's for us poor scumbags who shouldn't be put in charge of the cleaning staff at XCOM, let alone the entire organisation. OK? OK. SO, first things first...

Your first playthroughs are always the hardest. If you're struggling to even beat the game once just remember, the game makes it easier for you once you've beaten it once by giving you the option to Save Scum, so keep hammering your head against that wall because what's on the other side is definitely worth it.

That said, many people probably think it's "unfair" or "not in the spirit of the game" to abuse the save system. Well, those people are alien sympathisers who should be shot for treason. You are the ****ing COMMANDER. The ENTIRE WORLD is relying on you to use every tool at your disposal against the enemy, so save the game as often as you can. If the slightest thing goes wrong, reload.

The game has an autosave feature, but it delights in pulling fast ones and not saving every turn so you have to do it yourself. Save manually every turn. About to run into the unknown or do something risky? The quick save button, F10, is your friend, but they are a very jealous friend, so if you're taking the slightest risk on that same turn, you'll want to manually save or roll the dice because if you hit quicksave again the previous quick save is gone.

Keeping a library of saves in every encounter can mean the difference between being sent back 1 minute, being sent back 1 hour or packing up and giving up on the game. A save just before the start of an encounter is vital. A save every turn is vital as you can easily realise you screwed yourself 5 turns back.

If you miss a shot and try reloading and attempting the exact same shot, be prepared to have a bad time as the game remembers. Doesn't matter if you had a 5% chance desperation shot or a bogus 95% "How the **** did that one miss" gamebreaker, the game remembers you missed and won't show mercy. This is where having a plethora of saves is a lifesaver. Going back a bit and setting up a shot with the guy you missed with from a different spot or angle, or doing a different action like overwatch or suppression, or even just running away to better cover and crying in the corner like the little baby coward that you are, is all needed to survive. Try to minimise injuries your soldiers get by abusing this system too: you never know if the game is going to pull a fast one by dropping 3 missions on you in 3 days, and if half of your best men are injured in that first mission you could be screwed. Figuring out the balance between reloading far enough back to have a chance, but not so far back that you're losing too many precious minutes of your worthless life can be a tricky science to figure out, but I figured it out a heck of a lot faster than I figured out how to play the game legitimately, so you'll get there.

As a side note that fits no-where else, it is also always worth dropping in a cheeky little save whenever you are attempting to interact with an object, e.g. opening a door, pressing a button, opening a door, picking up meld, opening a door, or even when you need to open a door. The game controls amazingly well in all situations except this one, when it will happily assume, instead of having a soldier simply interacting with an object, what the player actually wants to do is send that soldier running around/through that object and wave their vulnerable ass at the 3 aliens lining up a shot across the room.

It's also important to save frequently outside of missions, saving at the start of the month and leaving saves each time you fast forward time. Realising you should have started building something necessary for survival 5 days ago, or that you should have tried to redo a mission with less soldiers injured because the game is throwing another mission at you 14 hours later that you have no chance of winning with the survivors, is heartbreaking, and while reloading and losing potentially a lot of progress is demoralising, it's truly the lesser of two evils.

If you ever get complacent with your constant saving, thinking "Hey, this mission ain't so bad" or "I'll try this one legit" or the ultimate blasphemy "Ha, I actually understand the game now, no need to abuse the saves anymore" is tantamount to suicide. The game will notice you're trying to play fair and it will ruin your life.

Trust me, I know.

With the combat system sufficiently abused, it's time to take a look at the satellite system. This is ultimately what everything in the game is about: once you have a full set of satellites up and running over every country, the encounters you get are much less, panic stops being such an issue, the bonus the countries give you make everything easier and you really start to rake in all the money. But getting your economy off the ground while also buying the gear you need to survive the missions can be a nightmare. In order to make it through the game with all the countries intact (because I tend to rage the moment a nation drops out), here's what you do.

1) Starting location
Turning off the tutorial is essential: after your first, no doubt disastrous, playthrough you know how to play the game and North America and Europe suck as starting locations. Also, each solider who gets just one kill in the starting mission gains a promotion, so play your cards right and you have 4 Squaddie rank soldiers right out the gate, rather than the pity heavy the tutorial gives you(Credit to user Rattus Rattus for that handy titbit). What you want is Africa. The pro's all harp on about Asia being great but, let's be honest, if you've made it this far into this guide, you are not a pro, so Africa is the place for you. It grants extra money which you'll need to get those satellites up and running.

2) Moar Satellites!
Try to always be building satellites to fill your allotted slots. If you can afford it, start building them even when you don't have the slots for it yet, as rarely will a country go into panic and leave enough time for you to build one before it leaves. This feels like it should be so essentially obvious that you would have either figured it out or died/raged because of it before Failed Playthrough Number 3 that I hesitate to even mention it, but in case someone out there missed it, playing the game with that in mind is vital.

3) Tactical Abductions
The game does an abduction mission about twice a month. Each offers a difficulty rating and a reward: this is NOT your priority. Your priority is panic. Each country has a 5 point rating until they go into panic. An attack directly on a country ups panic by 2, while every other country in the continent goes up by one. Beating an abduction mission reduces panic in that country but not continent wide. If the aliens are attacking a yellow country, it will go into panic if you do another mission. If there's an orange country in a continent that you don't do the mission for, it will go into panic. At the end of the month, if a country is in panic, it will leave XCOM and the game will get harder so pick which abductions to do based entirely on this. You develop a feeling as the game goes on. If you read the previous section, you should have saves before you start missions so if you realise you made a mistake with the first abduction of the month (the game revels in giving you a terror mission in the continent you just saved from an abduction, then launching abduction missions in those you left), suck it up and reload and try elsewhere. That being said, if you find they're attacking equally calm areas, going for bonus engineers or money early on can be a real life saver because of...

4) Satellite Uplinks/Nexus
To get satellites into space, you need the buildings to do it. You start with the ability to build uplinks and after researching the Alien Nav Computer (it's a necessity to do this research in good time by the way) you can build nexus'. The ideal configuration is a 2x2 box with 2 uplinks and 2 nexus', as that'll give you the ability to cover every country when you take the adjacency bonus into consideration. You need money, engineers and power to get these up so avoid frivolous spending, try to get some engineers in the abduction missions early on, splash out on a thermo generator if you can or just build a normal generator or two around a thermo vent if not. Dish out money on an extra satellite whenever you can afford to. If you're low on engineers you'll have to build a workshop, make sure you build in an area with space for another 2x2 grid for later workshops/foundry/mec factory/etc, as their adjacency bonus makes everything cheaper which is always good.

5) When to put Satellites up
In order to survive, you'll have to resist putting satellites up until the last possible moment. If you ignore the rest of the guide, fine, but this is genuinely important. Once you have the infrastructure to put satellites up, it's vital that you hold them back until you need them: deploying a satellite reduces panic, and it's the ONLY guaranteed way to calm down a panicked country. Once deployed, try and get an aircraft in that continent quick (buying new and transferring with the starter aircraft takes the same amount of time, so whatever). Once you finally have your first nexus up, you can start doing full coverage of continents despite the individual countries panic ratings: prioritise those continents that you already have satellites on, as abductions can still raise panic levels if they attack other countries on the continent, and the satellite is only a one chance reduction. If India or wherever is sat there with a satellite on it when it goes into panic because the game keeps launching abductions into Japan, you're basically screwed.

In XCOM, you never seem to have enough money, until you have your Satellite network up after which you have more than you know what to do with. One often overlooked little feature that the game doesn't really tell you about is the Gray Market, found in the Situation Room menu. Here, you can sell all the items and stuff you pick up from missions. But which do you sell so you can survive the next month, and which do you keep because in 3 months your lack of them will come and bite you in the bum? I'm sure other guides go into a little more detail, but lets sum up:

Corpses
Mechtoid, Sectoid Commander and Muton Elite corpses are useless after the initial research. Some you only need a few corpses handy for foundry projects after research: for Mutons you need to hold 6, Drones 10, Heavy Floaters 6, and for Sectopods you need 2 handy for when you get round to them. Sectoids, Floaters and Cyberdiscs make single use items for dogfighting, so keep all of them if you like using them (though you end up with so many Sectoids throughout the game, you may as well sell off a few if need be). The rest are used to build equippable items, so this is more up to you whether you want to keep or sell the corpses, figure out whether you reckon you've got enough of the item they build already and sell off the rest, whatever.
It can be worth keeping some of each corpse in case you get asked to give them, or an item you use the corpse to make, to a country for money, engineers, scientists etc., but the game delights in asking you to give away crap you haven't had the chance to get yet, until you have no need for money anyway (e.g. Germany or someplace asking for 4 Muton corpses when you've only killed 3 so far).

Alien Swag
You'll be picking up a lot of Weapon Fragments, Alien Alloys and Elerium as you play: this crap is important, so don't sell it. UFO Flight Computers and UFO Power Sources are pretty useful, but also valuable to sell: 40 quid for the computers and 75 bucks for the power sources. You need a lot of flight computers for building nexus', firestorms, etc. but 75 big ones for a power source...you need 1 power source for a firestorm, so keep 5, and you use 2 for each Elerium generator so I'd say don't sell any for the hell of it, but if you're desperate selling one off won't ruin you. All other swag is useless so sell that crap on, this will include broken stuff which is worth less but it's broken so who cares?

EXALT Garbage
You pick up the weapons from EXALT operatives you kill. Initially, these are just the basic weapons all your guys have anyway so there's no gameplay benefit to keeping and equipping them rather than just selling them on. You can be like "oh, these look cooler, I'm going to keep them" which is an attitude you can't afford if you suck enough at this game to be reading this guide. After a bit, the EXALT people start using laser weapons: sometimes you're developed enough that all your people have laser weapons anyway, other times you've only just started researching them so having a few extra is handy. They never use shotguns so if the stars seem to be aligning this way, invest in them first. If they start using lasers and the base attack hasn't happened yet, start equipping all your spare dudes with laser weapons from the top down. Like the corpses, rando countries will occasionally ask for EXALT stuff so hold a bunch in reserves if you want but I've only had this happen once so I don't bother.

Slingshot can go to hell
Apparently this DLC is somewhat randomised as to when the game begins it, but for me it always drops on me waaay too early, giving me my first encounters with various enemies before I'm really equipped to handle them. The first mission isn't so bad but about a month after beating it the game will drop 2 very hard missions on you back to back and, sensing your weakness, the game will often throw an abduction or something just before and/or after for good measure. This first bit is the first "great filter" of the game. If you haven't beaten the game yet and you have this DLC, you're better off dropping it when you start a new game, the benefits aren't worth it.

Failing in the Air
The stupid little airfight minigame will happily mess you up whenever it feels like. The only way to minimise risk here is to make sure you have an AIM item (got from sectoid autopsy) and a defence matrix (got from floater autopsy) and that your fighters are equipped with good weapons. The first one you get is the phoenix cannon which....isn't much of an improvement. The laser cannon is pretty effective if you activate the dodge immediately. The plasma cannons are when you have a good chance against anything they throw at you, particularly if you get a firestorm in each continent. It takes time to equip weapons, so remember to keep saving and scouting ahead. If times are desperate with money and aircraft weapons, you can combine abusing the save system with swapping out a single set of your best available weapon to wherever the UFO is.

MEC life
When you first research Meld and the scientist and the engineer are bickering over who is best, make sure you ignore the German lady. While the gene mods are cool, the MEC is what won me my first game (yes, I never beat OG XCOM, though I did make it to the final room of the final level only to get slaughtered time and again until I gave up). Build the MEC lab as soon as, it's not too much, and then get a MEC up and running. There's a lot of drama llama online about which class to upgrade when, but what's important is getting one as soon as you're able, and using a class which you can spare: if the game decides to give me 5 heavies, 2 supports, 1 sniper and 1 assault, I'm going with one of my heavies.

Officer Schmofficer
The two squad size upgrades are essential, get these as soon as you can. The others are all nice but not worth bothering with until your economy is really going, unless you come into a bunch of money and lack anything else to spend it on, in which case the one which halves injury time is a good buy.

Foundering at the Foundry
A few of the upgrades you can get at the foundry are game changers. As soon as you can build and unlock it, go for the Stealth Satellites one: if you screw up a UFO intercept, this will save you. Once you can afford it, tactical rigging is also amazing. After those 2, most of them are nice but largely unnecessary until you've got Asia covered in Satellites and your economy is really going. The Shivs are essentially made useless by the MECs, so don't even bother.

Class Inequality
The game delights in giving you a load of one class and being real stingy with the others. In the early game, try and bring at least one rookie with you on every mission and try and give yourself at least 2 of each class so you have someone in reserve if injuries start piling up. Chances are the game will hold one type of class back anyway, but you might get lucky. Swap these out as much as you can so you don't have a B-Team that feels like an F-Team when your main squad gets injured.
In terms of what upgrades to give your troops, giving a support all the medic-based abilities is so obvious it hardly seems worth mentioning; making sure you give your assault lighting reflexes is a must and the double shot upgrade is way more useful than the flush shot one. And as for the heavies....they're super slow and always seem to miss anyway so go with whatever suits you. Essential though is getting a sniper with squadsight: this one trooper can carry a mission on their own once you learn where to place them, and it's worth getting the pistol upgrade too: the other option would be nice if the game was always ideal, but it's not so better get that one for emergencies. IF you're lucky enough to have 3 snipers, having a squadsight, a spare and then a sniper with the alternate upgrade is good: this other sniper makes a good 6th option on missions alongside one of each class and a MEC.

Holding back
I said earlier not to do the tutorial because the starting locations are total junk. On top of this, the tutorial also rushed you through the early story missions. It's worth avoiding story missions in favour of building up your satellite network, finishing research, getting items, etc as the enemies get harder as you progress. The alien base attack where you need a skeleton key is a fine example of an opportunity to sit back and try and progress financially and technologically: there's no downside to just having the key and not attacking like with every other mission that pops. You will be gaining panic from abductions as you wait but you can launch the mission the moment things become unsustainable with panic ratings as finishing the mission reduces panic everywhere by 2. After this mission, the game becomes much more beatable as your soldiers are more effective, you have better weapons, etc. You can think of this as the 2nd "Great Filter", as the mission itself is challenging, and the game won't feel this hard until you approach the end. After this mission, the base attack randomly hits at some point. Assuming you're saving constantly, you can always reload to kit your team out fully.

Another good opportunity to hold back is by not building the Hyperwave Relay until you're ready for it. I'd call the mission following this the 3rd "Great Filter" but so long as you're ready for it, it isn't all that bad. What's important is to research the firestorm and then build one for each continent you have satellites in before you build the Relay. At this point, you should have a nexus and picking North America to cover can be very handy as it halves the cost of the firestorms and the weapons you can equip them with (plasma cannons are ideal).

Gene Mods
All the gene mods are quite nice, but there are one or two essential ones to get. Having an assault get the bioelectric skin early essentially cancels out the seeker enemies so long as you run the assults at the area they disappear in when you spot them. Giving your squadsight sniper the super jump legs is also great for getting them into positions where you can shoot across the entire battlefield. The mimetic skin is awesome for practically anyone as you can use them as a scout to find groups of enemies without alerting them, but it's expensive so hold off until your economy is really going. The brain ones become very helpful after the Hyperwave Relay and the eye ones are very cheap and available instantly so you might as well get them. Be aware that a single upgrade takes a soldier out for 3 days, so if they're an essential soldier feel free to save and scout ahead 3 days to check if you'll need them. I tend to do gene upgrades just before the council report comes in as random missions seem less likely to happen, but with this game you never know.

Psychic Shenanigans
10 days is forever. If you're crazy and you kept the slingshot mission on, Zhang is a guaranteed psi adept so running him through is a good bet. The people you get in the progeny missions are all guaranteed psi users as well, so the best strategy here is to pick one of the ones you unlock and make them your 6th party member. Train them up to match your team, using mindfray at any opportunity to train the psi skills up. The 1st rank you unlock is garbage, so pick anything, but go for the mind control one at the 2nd rank, it can be insanely useful.

Having had a couple of comments along the lines of "Why no SHIV?", I've decided to address it. SHIV's are basically these little robot drones you can bring along in place of a soldier that you gain access to and upgrade via the Foundry. I had a bad experience with SHIV's early on where I guess the game sensed I was trying something new and said to itself "Not on my watch" and I quickly went from building my first SHIV to dropping the playthough within a month of game time, and the only other time I used them was in the very late game one time to get an achievement. I found them expensive to upgrade, inaccurate, and very slow to build and repair, particularly as you have to build brand new ones for some of the upgrades. I can only imagine investing in them in the late game and by then you should have a super squad of colonels anyway, and so I have always got by in the game totally without them. But it's your game, feel free to try them out on a playthrough (particularly if you're starting in Asia as they'll be half price) if you've been having trouble beating the game and maybe they'll do the job for you, particularly if you only have OG XCOM as I guess they fill the role of a MEC in a pinch.

A quick note on prep: The Gollop Chamber is another good time to hold back (you can build it whenever, it's like the alien base mission in that you can choose whenever you want to begin once it's built). Make sure you have all the equipment you could possibly need, get every upgrade and piece of equipment you can. By now you should have full coverage so abductions won't happen anymore, and you've probably cleared out EXALT by now too. The missions the game throws at you now are either random council missions (most of these are a total joke in difficulty) or UFO/terror attacks (somewhat harder, particularly if you bump into a battleship, but by now you should have a super team and the odd injury is less likely to matter so nothing like the difficulty of the early game). You can keep playing the game at this point indefinitely, so there's no reason not to click the Gollop Chamber button without everyone fully healed up and equipped.

But now, at last, you've made it. The Final Room. You'll know this room when you see it. In the final mission, after fighting through each type of enemy and facing off against a couple of elite mutons, is a long, 1 space wide corridor. This room will happily dash your hopes of beating the game if you waltz in unprepared and is probably the last Great Filter: it stopped me on OG XCOM, it stopped my friend who is way better at these sorts of games than me and he has still never beaten it and, most likely, it will stop you too the first time you see it. The best method I've found is to have my psi adept mind control one of the elite mutons you get just before the room. IF this isn't possible for whatever reason, send your psi adept in first and have him mind control one of the elite mutons you get in the room: not ideal, but still workable. Abuse the save system and figure out the limit of where you can send either one without triggering the encounter, then have everyone line up behind them. Don't take too long or the mind control will run out. Once everyone is nicely lined up, send the muton charging in. He is your bullet sponge. Send everyone in but try not to bunch up too much or you'll risk a psi storm attack ruining your day. A death or two here isn't too bad as it's the end of the game. The essential knowledge for this room is that the boss guy directly opposite you is the target: once he's dead, it's all over. So ignore the others and concentrate fire on him. Squadsight sniper is great, particularly if you have the double tap upgrade. Your MEC should also do well. You've probably trained yourself not to use explosives but ignore that instinct if your heavy gets a chance with the rocket. If all goes well, the enemy will only get off a max of one volley of attacks before you take the big baddie down and you finally get the chance to smash your keyboard with excitement rather than rage at this bloody game.

Now you've beaten XCOM and are wondering where to go in the game from here. A harder difficulty perhaps? Maybe that long war mod everyone online can't get enough of? JESUS CHRIST NO! If you beat the game anything like I did, you'll probably never be good enough for that, I know and accept that I'm not. What you have access to now though are the second wave options. Most of these are meh, but wedged in there is the holy grail of the inept commander: SAVE SCUM! This means when you reload a save, the randomiser for whether you hit an enemy or not is reset, so if you play again, the times when you'll have to reload more than a turn back in an encounter will drop drastically. Plus, you now know everything you'll be facing. Since beating XCOM for the first time after numerous failed attempts, I've only bailed on one playthrough, which is the source of my very final piece of advice: as cool as it sounds, on second wave, don't go for the marathon option unless you want all the countries to panic and leave before you have even the slightest chance to do anything about it.

After replaying the game like this a few times, I admit to feeling confident enough to playing the game on Normal with the Save Scum on, but not bothering to reload at all. The game still pulls cheap shots on you, but knowing how it all plays out from beginning to end, where enemies like to spawn, the structure of the maps etc., it makes everything a lot less terrifying. Though it'll still pull some serious Bull, which I'll leave you with.

Excerpt from my last game: missed both rapid fire shots with my only assault on an enemy 2 inches away with a 95% chance to hit, it turns around and crits him for an instant kill and, while I cursed RNJesus for being a cruel and unfulfilling lord and master, I didn't reload that rubbish and came back to beat the whole campaign.