Every soldier who joins the XCOM project starts out as a mere rookie. Armed with only a basic assault rifle and a single frag grenade, these inexperienced lads and ladettes have to be clever and careful if they want to survive.



* Will is increased by 1-6+2 for every rank up, plus an additional 1-4+2 with the Iron Will perk
** The information in this table does not apply if the Second Wave modifier Not Created Equally is selected upon starting a new game


Nano-Fiber Vest[xcom.wikia.com] [Health +2] / Chitin Plating[xcom.wikia.com] [Health +4, melee damage taken reduced by 50%]
S.C.O.P.E.[xcom.wikia.com] [Aim +10]
Frag Grenade[xcom.wikia.com]
Medikit[xcom.wikia.com] [if squad lacks dedicated Support]

Making sure your rookies stay alive should always be your top priority. Even if they don't fire a single shot over the course of a mission, they will still receive experience points and ultimately climb in rank if they take part in successful missions.

To that end, it is probably best to equip your rookies with Nano-Fiber Vests. It probably won't save them from dying to a critical hit, but early on that +2 bonus to health can easily make the difference between injury and death.

If you fancy a more offensive playstyle, equipping your rookies with a S.C.O.P.E. to improve their aim is a good idea. Those Sectoids you encounter early on can be hard to hit when they are in high cover or far away.

Alternatively, giving your rookies Frag Grenades can make surviving early missions considerably easier. Rookies may have poor aim, but they can lob a grenade just fine. Use them to either destroy the aliens' cover or kill them outright. A solid tactic, but don't expect Dr. Vahlen to be happy about it:

"You may want to instruct your men to exercise restraint when using explosives. While certainly effective at killing aliens they also destroy the artifacts we're hoping to recover from their bodies. Just something to consider".

Only ever give a rookie a Medikit to hold if your squad does not have a Support soldier. Giving it to anyone else will effectively waste their valuable item slot, hurting their chances.

The aggressive Assault class is great for recon, flanking, blitz tactics and capturing aliens alive with the Arc Thrower[xcom.wikia.com]. They are not as durable as the Heavy, but their nimbleness paired with their defensive abilities keeps them alive even if they get caught in alien crossfire. Though they prefer the shotgun, an Assault soldier can also carry assault rifles into battle.


* The information in this table does not apply if the Second Wave modifier Hidden Potential is selected upon starting a new game



Squaddie: Run & Gun - every Assault promoted from rookie status acquires the Run & Gun ability, and it is awesome. Being able to fire (even Rapid Fire!) after dashing really helps when trying to flank an enemy, and it's also great for closing the distance on enemies that are hard to reach otherwise.

Corporal: Tactical Sense - Although Aggression is nice, Assaults generally have plenty of crit chance as it is, especially when flanking or attacking from stealth with Ghost Armor[xcom.wikia.com]. Also, to reach Aggression's full potential the Assault has to be within line of sight of three aliens, which can be very dangerous indeed.

Being front-line fighters, Assaults need all the extra defense they can get, especially on higher difficulties where aliens receive bonuses to Aim. This makes Tactical Sense a much better choice. Be advised that Tactical Sense has no effect against melee enemies such as Chryssalids.

Sergeant: Lightning Reflexes - Lightning Reflexes is hands-down the best ability here. With it you can force an enemy in Overwatch to waste its reaction shot on you without taking any damage. This in turn allows cornered squadmates to retreat to safety. The importance of Lightning Reflexes' many possible applications cannot be overstated.

Close & Personal is a solid choice for a second, more damage-oriented Assault, especially if you did not take Aggression at corporal rank.

Lieutenant: Rapid Fire - Rapid Fire is great in tandem with Run & Gun; run straight up to the enemy and blast them in the face twice at point-blank range. The damage potential is huge, and at short distances the -15 penalty to Aim is negligible.

By itself, Flush does terrible damage compared to Rapid Fire. It has some situational uses, such as forcing a well-fortified enemy out of cover while the rest of your squad is on Overwatch, but chances are good said alien will just take cover somewhere else straight away.

Captain: Close Combat Specialist - Close Combat Specialist will save your hide on terror missions, when you are surrounded by Chryssalids and Muton Berserkers. You can even trick Berserkers into charging you by shooting them from a distance; if they close to within 4 tiles you get a shot at them for free. Vital.

Bring 'Em On is a solid choice for the more offensive Assault, especially if you went with Close & Personal at sergeant rank. The enemies don't even have to be in the Assault's direct line of sight for the damage bonus to work, making this a potentially powerful offensive ability.

Major: Extra Conditioning - all Assaults that attain major rank gain Extra Conditioning. Have your Assault wear either Archangel[xcom.wikia.com] or Titan Armor[xcom.wikia.com] for the full +4 bonus to Health. Ghost Armor will give you +2 Health with this ability.

Colonel: Resilience - no matter how careful you are, at some point your Assault is going to get shot. At higher difficulties, chances an alien will score a crit against you increase dramatically. Resilience makes the Assault immune to critical hits, even when flanked. Take this ability and never look back.

However, if you went with Close & Personal and Bring 'Em On before, you have to take Killer Instinct here. If you use Run & Gun to dash right up to the enemy and then Rapid Fire at point-blank range, this deadly combination of abilities pretty much guarantees two critical hits at 150% damage, plus 1 damage for each enemy your squad can see. That's about 15-25 damage per shot with an Alloy Cannon[xcom.wikia.com]. Boom.


Nano-Fiber Vest[xcom.wikia.com] [Health +2] / Chitin Plating[xcom.wikia.com] [Health +4, melee damage taken reduced by 50%]
Arc Thrower[xcom.wikia.com]
Combat Stims[xcom.wikia.com] [Will +40, Mobility +3, 50% damage reduction and crit immunity for 2 turns]

Assault troops usually fight in the vanguard, exposing them to enemy fire. Good defense is a necessity and because of this, equipping your Assault with either a Nano-Fiber Vest or Chitin Plating is a must. Chitin Plating is an absolute no-brainer on terror missions and will help you deal with those pesky Chryssalids. Of course, you will have to kill one before you can make any.

The Assault's close proximity to the enemy makes them ideal candidates for carrying the Arc Thrower into battle. Be advised that the Arc Thrower isn't considered a weapon and therefore cannot be used with the Run & Gun ability. Soften enemies up from a distance and rush in with the Assault to take them in for 'questioning'.

Combat Stims are another great choice for Assaults to carry, especially for those that prefer offensive abilities. Note that using it ends the Assault's turn.

The Heavy is a hulking powerhouse, capable of dealing massive amounts of damage to synthetic enemies.. and pretty much everything else around them. Armed with a light machine gun and a rocket launcher, these bad boys carve a path through obstacles like no other.



* The information in this table does not apply if the Second Wave modifier Hidden Potential is selected upon starting a new game



Squaddie: Fire Rocket - The Heavy's signature weapon is the rocket launcher. Use it to dispose of cover, exposing the enemy, or to blow up explosive objects such as cars. Everything caught in the blast will die, including your squadmates. Make sure you have a medic standing by.

Corporal: Bullet Swarm - This ability allows you to fire your weapon and then move, shoot again, go into Overwatch or reload. Needless to say, Bullet Swarm is a versatile ability that's easily more useful than its counterpart Holo-Targeting.

Sergeant: Shredder Rocket - Every once in a while, especially on terror missions, you are going to get swarmed. Whether facing a zerg rush of Chryssalids or a small army of Mutons, Shredder Rocket is your ticket out of a sticky situation. Use it to soften up the masses and then clean up with a grenade. The Shredder Rocket also doubles nicely as a terraforming tool.

Suppression is not a terrible ability, but it consumes ammo both when you activate it and if the Heavy takes a reaction shot. This could mean you start your next turn with an empty gun, and that's a pretty afwul situation to find yourself in.

Lieutenant: HEAT Ammo - This ability DOUBLES all damage you deal to synthetic enemies; that includes Cyberdiscs and Sectopods. With HEAT Ammo your Heavy will one-shot Cyberdiscs every time, and if you took Bullet Swarm your Heavy can single-handedly topple a Sectopod in one turn as well. HEAT Ammo isn't just good, it's vital.

Rapid Reaction is terrible because it relies on the first reaction shot to hit. Heavies have terrible Aim and on top of that, there's an Aim penalty on reaction shots. Even if by some miracle the first shot connects, your special second shot can and very likely will miss, making this a godawful ability.

Captain: Danger Zone - This ability is pretty great, but it's also a double-edged sword. Being able to catch more enemies in one rocket's blast radius is awesome, but the increased damage radius also means it's easier to hit your own guys with it. It also makes it a bit trickier to blow up cover without killing the aliens cowering behind it; the raw damage potential more than makes up for these little drawbacks, however.

Don't take Grenadier. You will need a S.C.O.P.E. on your Heavy to compensate for his terrible Aim and on top of that, if you take Shredder Rocket and Rocketeer you will have a total of 3 rockets available on every mission. Use any more explosives than that and you will find yourself wanting for salvage before long.

Major: Will to Survive - If you position your Heavy with care, this ability will really help him survive. With this, chances are good the Heavy won't get hit for more than his armor can shrug off, meaning no more visits to the infirmary!

Colonel: Rocketeer - This is a tricky one. The extra damage on rockets from Mayhem is nice if you don't use more than one or two of them per mission, but if you didn't take Suppression (and I recommend that you don't) the usefulness of this ability is seriously hampered.

Rocketeer gives you one extra standard rocket per mission. Point for point, that is more bang for your buck than the damage bonus from Mayhem, making Rocketeer a solid choice, especially in combination with HEAT Ammo (yes, it applies to rockets too!) and Danger Zone.


S.C.O.P.E.[xcom.wikia.com] [Aim +10]
Combat Stims[xcom.wikia.com] [Will +40, Mobility +3, 50% damage reduction and crit immunity for 2 turns]

Heavies are terrible shots. Early on, when you have to make do with one rocket and your LMG, you will want to make every shot count. The +10 Aim bonus of a S.C.O.P.E. is a godsend for inexperienced Heavies.

Later on, when your Heavy has attained colonel rank, trading that S.C.O.P.E. for a Stim Pack allows for some interesting tactics. Your Heavy, already a pretty durable unit, can soak up damage like a sponge with the Stim Pack's 50% damage reduction and crit immunity.

On top of that, the +3 Mobility bonus allows the Heavy to run farther, enabling him to get in close and shoot the enemy from point-blank range, negating the need for that S.C.O.P.E. altogether. And the best part? With Bullet Swarm you can fire AND use the Stim Pack all in one turn!

Snipers are the most terrifying addition to any XCOM squad. They can kill without being seen, or disable enemy weapons from a distance. Scaling buildings or taking to the skies in Archangel Armor to find that perfect vantage point, they oversee the entire mission area. Your whole squad will rest easy knowing that their Sniper is up there somewhere, looking out for them.



* The information in this table does not apply if the Second Wave modifier Hidden Potential is selected upon starting a new game



Squaddie: Headshot - The Sniper's signature ability is also one of its best. Once every three turns you can fire a shot with a 30% increased crit chance and extra damage based on weapon tech. It's pretty much a guaranteed crit if you flank an alien or catch one out in the open with it. It pairs really well with Double Tap and Ghost Armor[xcom.wikia.com] for landing two massive crits in a row.

Corporal: Squad Sight - Squad Sight defines the Sniper class. With it your Sniper can fire on any alien your squad can see, provided there are no obstacles in the line of fire. Without it, you have to waste valuable time setting your Sniper up on a good vantage point. Squad Sight means your Sniper spends less time running and more time killing aliens. Essential. Paired with Archangel Armor[xcom.wikia.com] this ability is godlike.

Snap Shot, although not without its uses, really is more trouble than it's worth. Using it properly means flanking aliens with your Sniper and that means getting in dangerously close, exposing yourself. Being able to fire the Sniper rifle after moving is nice, but Snap Shot does hurt the Sniper's impeccable accuracy.

Sergeant: Gunslinger - This ability is a godsend in confined spaces, and early on when the Sniper is still lacking some of his best abilities. With Gunslinger your Sniper will do surprisingly decent damage using a Laser[xcom.wikia.com] or Plasma Pistol[xcom.wikia.com], and it works just fine with Double Tap for those times when one shot just isn't enough.

Damn Good Ground is a nice ability in its own right, but Snipers have great Aim to begin with, especially on higher ground. The Defense bonus is nothing to write home about, either, and if you play your Sniper right he should not be exposed to enemy fire to begin with.

Lieutenant: Disabling Shot - On higher difficulties, sometimes you just know you won't be able to kill that last alien on this turn. Disabling its weapon is a pretty good alternative at that point. Disabling Shot allows you to waste the alien's turn by making it reload to fix its gun. It's also great for 'prepping' targets you want to stun with the Arc Thrower, minimising the risk of getting your soldiers killed should the stun fail.

If your Sniper took Snap Shot earlier, you might like Battle Scanner. It's great for peaking around corners without exposing yourself, but it has limited uses and does not work as well for Snipers that like to keep their distance. It will work with Squad Sight, which is nice.

Captain: Opportunist - Taking reaction shots that can crit without suffering an Aim penalty? If that sounds overpowered to you it's because it is overpowered. Opportunity turns your squad's line of sight into a murder zone. Any alien careless enough to step within range is going to get its head blown off. It works beautifully with pistols too, even over long distances. The Executioner ability does not even begin to compare to this.

Major: Low Profile - This ability means you can set your Sniper up anywhere you like. It lets you save obstacles that provide full cover for squad members who really need it, and makes ledges, balconies, rooftops and lorry trailers that much more attractive as vantage points.

Colonel: Double Tap - This is it; the hardest choice your Sniper will ever have to make: In The Zone or Double Tap?

In The Zone is excellent for those whide open spaces where you are going up against Cyberdiscs, Floaters, Drones, Chryssalids, Zombies or Berserkers, pretty much any enemy that does not take cover. As long as you can kill them with one shot and the shot connects, you can keep firing until you've emptied your rifle. It's hugely powerful, but very situational.

On the other hand, Double Tap lets you fire twice every other turn. There's a little less potential damage here, but it is much more reliable and less dependent on the situation. Double Tap works just fine with all special shots and if you use it with Ghost Armor and Headshot, you can score two huge crits in a row. More than enough to kill a Sectopod, or even the Uber Ethereal, in one turn.

If you went with Snap Shot earlier, pick In The Zone here. If not, I would strongly recommend taking Double Tap. Actually, I would always recommend it. It's both powerful and reliable and that makes it really hard to beat.


S.C.O.P.E.[xcom.wikia.com] [Aim +10]

The S.C.O.P.E. is probably the only item your Sniper will ever need. Early on, it's vital to compensate for the Aim penalty on reaction fire, and it negates the Aim penalty on Disabling Shot completely. It will also help you make the most of In The Zone and Double Tap, making the S.C.O.P.E. the obvious choice.

Sometimes things can get ugly; soldiers start taking hits and go down, or panic in the face of overwhelming odds. The Support is there to patch them up, strengthen their resolve and help them get back into the fight. These strong-willed warriors have good aim and run like the wind, providing covering fire for their squad or going the distance to flank enemies.


* The information in this table does not apply if the Second Wave modifier Hidden Potential is selected upon starting a new game



Squaddie: Smoke Grenade - Smoke Grenades are essential for those times when you need a soldier to get in position where there is no full cover to benefit from. It's a great ability, but you only have one per mission, so make it count.

Corporal: Sprinter - +3 to Mobility may not sound like much on paper, but it makes a huge difference. You could use it to flank an enemy that is pinned down, close in on an enemy to stun him with the Arc Thrower or leg it to stabilise a friendly that was shot down across the battlefield. Sprinter is a subtle, but powerful ability.

Covering Fire is not bad, especially on higher difficulties, but it has one major flaw: your Support will only take a reaction shot after the enemy has fired, meaning it could well be too late already. It pairs well with Sentinel later on, but it's not nearly as versatile as Sprinter.

Sergeant: Field Medic - Getting 3 uses out of your Medikit per mission instead of just 1 makes this an absolutely essential ability. Watching a wounded soldier bleed out because you used your one Medikit on a paper cut is rough; don't put yourself in that position.

You could argue that having 2 Smoke Grenades per mission would allow you to prevent those wounds in the first place, but relying that heavily on Smoke Grenades is risky, especially on higher difficulty levels where the aliens receive bonuses to Aim.

Lieutenant: Revive - No medic can do without Revive. It's essential, especially in those Ironman games where every veteran soldier is worth his weight in gold. Not only can you prevent them from dying, you can actually put them straight back into the fight. Awesome.

Rifle Suppression uses up a lot of ammo and unless you took Covering Fire earlier, you are probably not going to get much use out of it. A suppressed alien knows better than to move when under fire, and at higher difficulty levels chances are good they will still hit you, even at a -30 penalty to Aim.

Captain: Dense Smoke - This is a pretty tough choice, but Dense Smoke is the slightly better choice here because the area of effect on it is bigger than that of Combat Drugs, and because +20 Defense is generally better than +20 Will and a +10% crit chance, which is negligible. Defense works against all enemies, whereas Will only really helps you against psionic abilities.

That said, Combat Drugs is not without its uses and having a second Support with this ability could be a great idea. You could use it to empower your gifted soldiers or keep soldiers with a low base Will stat from panicking in the face of terrible danger.

Major: Deep Pockets - It may be a passive ability, but Deep Pockets is a-ma-zing. You could carry both a Medikit and an Arc Thrower, or Chitin Plating and a Mind Shield, or any other combination of offensive, defensive and utlity items. Deep Pockets is a defining ability for the Support and it makes them the most versatile class by far.

Colonel: Savior - Again, this is a very tough choice because both abilities are pretty great. Savior is fantastic because it doubles the effectiveness of your Medikits. If you completed the Improved Medikit project in the Foundy, this bumps your Medikits up to +10 Health per use. Awesome.

Sentinel is great too, as it allows you to fire from Overwatch twice. Unlike the Heavy's Rapid Reaction ability, the first shot does not even have to be a hit for it to work. Sentinel is great when you're trying to lure enemies into a murder zone, but it has one major flaw: the second shot will never trigger on enemies that you run into for the first time.


Medikit[xcom.wikia.com]
Arc Thrower[xcom.wikia.com]

Every Support should carry a Medikit. Supports are the best at healing squad members and their Deep Pockets ability allows them to carry another, more directly beneficial item as well. Also, the Medikit grants immunity to poison, which is excellent when fighting Thin Men.

The Arc Thrower is another great item choice for Supports, especially if you took the Sprinter ability. Supports can run long distances, making it easy for them to get into stun range. Should the stun fail, you could use your Assault to run in and clean up so nobody gets hurt.

Later, when capturing aliens alive is no longer a priority or even completely unnecessary, you could replace the Arc Thrower with any item you want. Chitin Plating is great for defense, especially on terror missions. Mind Shield will help your Support overcome psionic attacks. Combat Stims could improve their own psionic powers, etc. Take your pick, they are all solid choices.

After building the Psionic Labs, you can test your soldiers for 'the Gift'. All classes can become Psionics and they will get a special purple class icon to convey that they are gifted. Psionics can get inside the minds of their enemies, causing them to panic and fire on their allies. The most powerful Psionics can even deflect bullets with their mind, or make an alien do their bidding.

Note that Psionic soldiers can only gain ranks and access new abilities by actively using their powers. Use psi powers often and well to unlock new, even stronger powers more quickly.




Adept: Mindfray - Every gifted soldier starts out with this ability. Mindfray is an excellent power because it does not factor in distance or cover, making it a good choice against enemies that are in full cover. The penalties to Aim and Mobility make it a very good substitute for Suppression and the Will penalty makes the enemy more susceptible to panic or mind control.

Specialist: Psi Inspiration - This ability comes into its own against enemies like the Sectoid Commander and Ethereal. Being able to bolster your squad's defense against mental attacks is vital, and strengthening their Will to prevent panic is also important. You could even use it to improve another Psionic soldier's powers, improving their chances of nailing a Mind Control.

Psi Panic is a decent ability, but panic in itself is too unreliable to count on as a combat strategy. There's simply no telling what a panicked enemy might do: he could run away in fear, attack his own allies, or he could go berserk and fire on you again instead. Using Psi Panic is like rolling the dice and I would recommend against using it.

Operative: Telekinetic Field - It may be the safe, boring option, but make no mistake; Telekinetic Field is powerful. It adds +40 Defense to whatever Defense bonuses were already in place, and the area of effect is massive. This ability will save your squad from Sectopods and Muton Elites more than a few times before the alien invasion is over. Just keep in mind that enemies can benefit from it as well, so use it wisely.

Mind Control is an amazingly powerful ability that can really turn the tide in battle. With the right combination of gear, items and abilities, you could even use it to mind control an Ethereal, which will grant you an achievement if you succeed. It's also just really, really cool, but it has drawbacks. Unlike Telekinetic Field, it can fail, and if it does you won't be able to use it again for five turns. In the thick of a firefight, five turns is an eternity.

If you have more than one gifted soldier on your team, have one take Telekinetic Field and the other take Mind Control. Two Psionic soldiers working together spell disaster for the aliens.



Mind Shield[xcom.wikia.com] [Will +30]
Combat Stims[xcom.wikia.com] [Will +40, Mobility +3, 50% damage reduction and crit immunity for 2 turns]
Chitin Plating[xcom.wikia.com] [Health +4, melee damage taken reduced by 50%]

The Mind Shield's description can be deceptive. It's intended purpose is to shield the wearer from offensive psi attacks, but it can also be used to power the user's own Psionic abilities. Use it together with Psi Armor[xcom.wikia.com] to have a real shot at mind controlling those darn Ethereals. You will have to kill one before you can build it, though.

Going with Combat Stims is good if you can't build the Mind Shield yet. The +40 bonus to Will is excellent and the damage reduction certainly does not hurt either. You can use this to empower your Mind Control ability, but remember that it takes up a turn to use it. Don't leave your soldier exposed while the stimulants take effect.

Of course, you could argue that a Psionic has plenty of mental defenses as it is, especially if wearing Psi Armor. You could therefore decide to bolster his physical defense, and that's where Chitin Plating comes in handy. +4 to Health is nice, especially considering Psi Armor is medium-class and only provides +6 to Health, rather than Titan Armor[xcom.wikia.com]'s +10 Health bonus.

A NOTE ON PSI ARMOR
After clearing the Overseer Crash Site[xcom.wikia.com], XCOM's second essential story mission, you will have the opportunity to research Psi Armor[xcom.wikia.com]. I strongly recommend developing it at the earliest possible convenience. Psi Armor grants a +20 bonus to Will, making it that much more likely your Psionic powers will work succesfully.

In this section you will find some tips that all tie in directly to your squad members and their abilities in some way. I will try to keep adding to this section over time, and I will see about adding some images or videos here and there to visually represent more complex ideas.


There are four different classes in XCOM: Enemy Unknown, and there's a total of six spots on your team. All classes have their merits, and as such the core of your team should simply look like this:

1 Assault
1 Heavy
2 Support
1 Sniper

I strongly recommend taking 2 Supports on your team wherever you go. They aren't the strongest fighters, but they are accurate and their versatility makes them an excellent addition to your team. Ideally, you will want one of them to focus on healing abilities, and let the other one take perks like Combat Drugs and Sentinel.

For terror missions and abduction missions, consider taking a second Assault. They are the best in close-quarters combat and any enemy stupid enough to run into striking range will be torn apart by their Close Combat Specialist ability. Assaults are the perfect counter against Chryssalids and Berserkers, and with Ghost Armor they make excellent spotters for your Sniper, too.

For council missions and UFO crash/landing sites, consider taking a second Sniper. Give them both Squad Sight and maybe a suit of Archangel Armor, and use the rest of your team as spotters. Snipers can deal a stupid amount of damage from afar and if one of them specialises in Double Tap and the other one takes In The Zone, they can lay waste to an entire army of aliens between the two of them.

• #1 rule: always have a backup plan! Soldiers can and will miss shots despite great odds at the absolute worst of times, and you will want to make sure they don't get caught with their pants down. Think about a move before you make it, and think about what could go wrong beforehand.
  
  
• Never dash. Seriously, just don't do it. You could argue that dashing is safe unless you are already engaged in a fight, but it's a bad habit regardless. Always move all of your soldiers once before committing to a second action with any of them.
  
  
• Make a habit of moving your Assault(s) first. If any aliens are on Overwatch beyond your line of sight, you have a good chance of wasting their reaction shot with the Assault's Lightning Reflexes.
  
  
• Always move your Sniper last. Should your squad stumble upon some aliens, taking an 'active' shot before the end of your turn is always more efficient than reaction fire from Overwatch, especially so if your Sniper knows In The Zone or Double Tap.
  
  
• Don't charge into unrevealed territory when you are already in a fight. Chances are more uninvited guest will crash your party, and that is going to make life really hard for you on higher difficulties.
  
  
• Check all your soldiers before firing a single shot. If your Sniper can hit only one alien and your Assault can hit three, make sure you don't have your Assault kill that one alien your Sniper could have killed instead.
  
  
• Take a turn to reload ALL guns after a firefight. If you don't, your soldiers could be out of ammo halfway through the next firefight, just when they're up against a Sectopod and a small army of Mutons.
  
  
• Similarly, never patch up soldiers in the middle of a fight. Doing so would likely expose your medic, risking more injuries or even death. It's better to pull injured soldiers away from a firefight and keep them away until the threat is dealt with.

• Consider colour-coding your soldiers based on class to distinguish between them on the battlefield more easily.
  
  
• Don't spread your shots out too thin. Injured aliens can still kill you just fine.
  
  
• If aliens are cowering in full cover, blow it up with a grenade or a rocket. Failing that, just blow them up with it instead.
  
  
• Mutons and Cyberdiscs will use this tactic against you if they get the chance, so don't huddle up your soldiers too close when facing them.
  
  
• Cars, trucks and UFO Power Sources make great bombs. If two or more aliens have positioned themselves around them, take the opportunity to blow them all to smithereens with one well-aimed explosive.
  
  
• Rookies couldn't hit an alien with their rifle if they were sitting on its shoulders. However, they make great grenadiers. It just takes one kill for a rookie to level up, so that one grenade should be all they need.
  
  
• Don't forget to use the Hunker Down ability! If you need to close in on an alien so you can flank or stun them next turn, minimise the risk of getting hurt by hunkering down behind cover. Hunker Down doubles your cover bonus and confers immunity to critical hits, which by itself can make all the difference.
  
  
• Even in full cover, you can and will still get shot. For a soldier to be truly safe he needs to be completely out of sight.
  
  
• Use your pistols! They are great for softening up enemies you want to stun and capture, and Snipers with the Gunslinger ability can kill plenty of enemies with them in one hit. They don't expend ammo either, making them efficient against weaker aliens.
  
  
• Pay close attention to the noises you hear whenever a soldier remarks something like "did you hear anything"? Learning to recognise the sounds that aliens make could provide you with important clues as to what you are about to face, and where the threat will be coming from.
  
  
• Give your fastest runner a suit of Ghost Armor and have him scout ahead in stealth. This way you can start picking off aliens with your Sniper(s) from as far away as the Skyranger's LZ.
  
  
• On terror missions, be as aggressive as possible without putting your soldiers at great risk. The better you perform, the more panic reduction you will receive afterwards.

Ain't No Cavalry Comin'
Have a soldier survive every mission in a full game.

You can do this achievement on any difficulty. It's a breeze on Easy, but I've been able to do it with three soldiers on Normal difficulty just fine. All it takes is for one of your original squad of four soldiers to come along for every mission in an entire playthrough. If you take good care of your Sniper and keep him out of harm's way, this achievement should not be too difficult to acquire.

Note that you can still do this if the soldier you depend on is hospitalised, as long as he is back on active duty before the start of the next mission.

Xavier
Mind Control an Ethereal. Single player only.

This is a tough one. Your Psionic soldier has to have a very high Will stat to be able to do it, and even then it's going to take plenty of buffs to even have a decent chance of success. Psi Armor is an absolute must, as is a Mind Shield. Have another Psionic use Psi Inspiration on you if possible, or use a smoke grenade with Combat Drugs. Stack as many Will buffs as you can before attempting the Mind Control to maximise your chances of success.

Note that doing physical damage to the Ethereal won't improve your chances like it would with stunning, but damaging him mentally with Mindfray will. However, an Ethereal is extremely hard to hit with Mindfray, so it might be more worthwhile to try other things.

Lone Wolf
Clear a UFO crash site with one soldier on Classic or Impossible difficulty.

There are two ways to tackle this achievement. The first and best way would be to take only your Heavy on the very first UFO mission you receive. This way, it's going to be him against 4 Sectoids and 1 Outsider, which should give you a pretty good chance of success. When in a pinch, don't hesitate to toss a grenade or use your rocket. If possible, try to save that rocket for the Outsider so a one-shot kill is all but guaranteed.

If you didn't manage to do this achievement in the early game, you can still get it much later down the line. Take one gifted soldier with Mind Control (preferably a Heavy) and use this ability to create allies for yourself. Muton Elites make the best candidates for Mind Control because they are easy to overcome and can deal hideous damage to their comrades. They will serve as your willing meat shield while you clean up from a distance. Just before the Mind Control wears off, have the alien commit suicide with an alien grenade and move on to the next target. Rinse and repeat.

Thank you, dear reader, for taking the time to read through this guide. I am a huge fan of XCOM: Enemy Unknown and this game has marked the first time that I've ever been invested enough in a game to write about it, help others with it and share my stories of triumphant victory and gut-wrenching loss with the world.

I am extremely grateful to the team at Firaxis for making this wonderful reimagining of an absolute classic. They have allowed me to experience the greatness of a franchise that I was way too young to appreciate when the original game came out. I've never properly played X-COM: UFO Defense and chances are that I never will, but thanks to XCOM: Enemy Unknown I now finally understand what made that game so special.

If you find something to like in this guide and if it was helpful to you, it would mean a lot to me if you took the time to drop a line in the comment section or leave a 'like' so that others might see and enjoy it.

Good luck, Commander. Rensje out.