Class Builds (EU2012)

Each class has been designed with two main ability builds, Alpha (left side) and Beta (right side). Each build is a combination of abilities designed to fulfill a specific tactical role. Although experienced players will design soldiers according to their own preferences, this article will focus on the basic builds available to each class, and how the different abilities on each one can synergize together.

Assault

Assault Alpha (Scout)

Rank	Ability	Alpha
Squaddie	Run & Gun Allows firing or Overwatch after Dashing on the turn Run & Gun is activated. 2 turn cooldown.
Corporal	Tactical Sense Confers +5 Defense per enemy in sight (max +20).
Sergeant	Lightning Reflexes Forces the first reaction shot against this unit each turn to miss.
Lieutenant	Flush Fire a shot that causes enemies to run out of cover. The shot is easy to hit with, but does reduced damage.
Captain	Close Combat Specialist Confers a reaction shot against any enemy who closes to within 4 tiles. Does not require Overwatch.
Major	Extra Conditioning Confers bonus health based on which type of armor is equipped. Heavier armor increases the bonus.
Colonel	Resilience Confers immunity to critical hits.

The Assault Alpha build is designed for evasion and survival, allowing it to excel in scouting roles. The two first abilities, Tactical Sense and Lightning Reflexes greatly increase the soldier's defense while Resillience allows him/her to soak hits.
Run & Gun give it the ability to easily finish off already wounded hostiles and set Overwatch over outflanked enemies.
Lightning Reflexes can be used to prevent an enemy on Overwatch from hitting anyone, by moving the Assault Alpha first before the other units.
Flush gives the Alpha the option to force an enemy to vacate a position. One possible combination of moves is to set other units on Overwatch before using Flush, giving them shots at the alien as it moves to another position. Flush is also the only medium range fire option the Assault Alpha has, unless he/she brings an Assault Rifle instead of the Shotgun.

Assault Beta (Assault/Rifleman)

Rank	Ability	Beta
Squaddie	Run & Gun Allows firing or Overwatch after Dashing on the turn Run & Gun is activated. 2 turn cooldown.
Corporal	Aggression Confers +10% critical chance per enemy in sight (max +30%).
Sergeant	Close & Personal Confers +30% critical chance against adjacent targets. The bonus declines with distance from the target.
Lieutenant	Rapid Fire Take two shots against a single target in quick succession. Each shot carries a -15 penalty to Aim.
Captain	Bring 'Em On Adds 1 damage on critical hits for each enemy the squad can see (up to 5).
Major	Extra Conditioning Confers bonus health based on which type of armor is equipped. Heavier armor increases the bonus.
Colonel	Killer Instinct Activating Run & Gun now also grants +50% critical damage for the rest of the turn.

XCOM's equivalent of the Berserker. The Beta build is able of charging and killing nearly any alien unit that comes within close range or it can act as a rifleman, depending on weapon choice (Shotgun/Assault Rifle).
Aggression, Close & Personal plus the Shotgun's own critical chance bonus turn most shots into critical hits. Rapid Fire gives it two shots and Bring 'Em On and Killer Instinct add even more critical damage to each one.
For engagements at medium range the Assault Beta can use its Rapid Fire ability for increased odds. The drawback is the ammo depletion that continued use of Rapid Fire will bring.
The Shotgun is the preferred weapon to take full advantage of Run & Gun and Killer Instinct. However, all of Assault Beta's abilities also apply to Assault Rifles, so Aggression, Rapid Fire and Bring 'Em On can turn the Assault into a deadly Rifleman.
It's main disadvantage is the lack of additional defense/armor other than that provided by Extra Conditioning, armors or Chitin Plating.

Alternate Builds

Rank	Ability	Gamma
Squaddie	Run & Gun Allows firing or Overwatch after Dashing on the turn Run & Gun is activated. 2 turn cooldown.
Corporal	Tactical Sense Confers +5 Defense per enemy in sight (max +20).
Sergeant	Lightning Reflexes Forces the first reaction shot against this unit each turn to miss.
Lieutenant	Rapid Fire Take two shots against a single target in quick succession. Each shot carries a -15 penalty to Aim.
Captain	Bring 'Em On Adds 1 damage on critical hits for each enemy the squad can see (up to 5).
Major	Extra Conditioning Confers bonus health based on which type of armor is equipped. Heavier armor increases the bonus.
Colonel	Resilience Confers immunity to critical hits.

Rank	Ability	Delta
Squaddie	Run & Gun Allows firing or Overwatch after Dashing on the turn Run & Gun is activated. 2 turn cooldown.
Corporal	Aggression Confers +10% critical chance per enemy in sight (max +30%).
Sergeant	Lightning Reflexes Forces the first reaction shot against this unit each turn to miss.
Lieutenant	Rapid Fire Take two shots against a single target in quick succession. Each shot carries a -15 penalty to Aim.
Captain	Close Combat Specialist Confers a reaction shot against any enemy who closes to within 4 tiles. Does not require Overwatch.
Major	Extra Conditioning Confers bonus health based on which type of armor is equipped. Heavier armor increases the bonus.
Colonel	Resilience Confers immunity to critical hits.

Heavy

Heavy Alpha (Demolitions)

Rank	Ability	Heavy
Squaddie	Fire Rocket Fire a rocket using an equipped launcher. This ability can not be used after moving, nor more than once per mission.
Corporal	Bullet Swarm Firing the primary weapon as the first action no longer ends the turn.
Sergeant	Shredder Rocket Fire a rocket that causes all enemies hit to take +33% damage from all sources for the next 4 turns. The rocket's blast is weaker than a standard rocket's.
Lieutenant	HEAT Ammo +100% to damage against robotic enemies.
Captain	Grenadier Allows to carry 2 grenades in a single inventory slot.
Major	Will to Survive Reduces all normal damage taken by 2 if in cover and not flanked.
Colonel	Rocketeer Allows 1 additional standard rocket to be fired per battle.

While 3 rockets and 2 grenades can be spent quickly during missions, the additional firepower of a Heavy Alpha can turn a battle around.
Any situation can be dealt with the proper use of explosives: close, medium and long range, either to kill aliens or blast away their cover.
Bullet Swarm allows for double shots or to fire and move, giving the Alpha more options during a firefight and can it deadly at close range.
HEAT Ammo is vital against robotic aliens such as Drones, Cyberdiscs or Sectopods
Their drawback is the Heavy's usual low Aim stat, which limits the effectiveness of their weapons at medium and long range.

Heavy Beta (Tagger)

Rank	Ability	Tagger
Squaddie	Fire Rocket Fire a rocket using an equipped launcher. This ability can not be used after moving, nor more than once per mission.
Corporal	Holo-Targeting Shooting at or suppressing enemies also confers a +10 Aim to any allies' attacks on those enemies.
Sergeant	Suppression Can fire a special shot that grants reaction fire at a single target. The target also suffers a -30 Aim penalty.
Lieutenant	Rapid Reaction Confers a second reaction shot, if on Overwatch and the first reaction shot is a hit.
Captain	Danger Zone Increases hit area of rockets and suppression by 2 tiles.
Major	Will to Survive Reduces all normal damage taken by 2 if in cover and not flanked.
Colonel	Mayhem Confers additional damage based on weapon tech level to Suppression and all area-effect abilities.

Heavy Betas are team players. Their role is to tag an enemy unit to increase the aim of other squad members firing at it (Holo-Targeting), suppress their shots (Suppression), keep an eye for enemy movement (Rapid Reaction), suppress more than one alien (Danger Zone) and deal damage to enemies under suppression (Mayhem), which may be the killing blow to an already weakened alien.
Despite being limited to one Rocket, both Danger Zone and Mayhem upgrade both the rocket's damage radius and power. The Heavy Beta may also first suppress a target to prevent it from reacting until it's ready to fire the rocket shot at the alien.
The disadvantage is the Heavy's usual low Aim stat, which makes Rapid Reaction less useful at long range Overwatch shots. At close range however, the low Aim is less relevant.

Alternate Builds

Grenadier + Mayhem gives an additional punch to grenades.
Shredder Rocket + Danger Zone + Rocketeer gives 3 rockets with extra blast range.
For maximum Machinegun firepower: Bullet Swarm + Suppression + Rapid Reaction + Danger Zone + Mayhem.
HEAT Ammo is very helpful to deal with unpleasant surprises such as Cyberdiscs and Sectopods.

Sniper

Sniper Alpha (Gunslinger)

Rank	Ability	Gunslinger
Squaddie	Headshot Fire a shot with +30% critical chance and extra damage on critical hits based on the tech level of the sniper rifle. 2 turn cooldown.
Corporal	Snap Shot Removes the sniper rifle's restriction on firing and Overwatch after moving. Any shots taken suffer a -20 Aim penalty.
Sergeant	Gunslinger Confers 2 bonus damage with pistols.
Lieutenant	Disabling Shot Allows the Sniper to fire a shot that causes the target's main weapon to malfunction. The target may use Reload to fix the weapon. The shot cannot inflict a critical hit. 2 turn cooldown. -10 Aim penalty
Captain	Executioner +10% Aim against targets with less than 50% Health.
Major	Low Profile Makes partial cover count as full.
Colonel	In The Zone Killing a flanked or uncovered target with the sniper rifle does not cost an action.

Sniper Alphas are mobile marksmen, designed to be experts with either the Sniper Rifle or the Pistol.
Snap Shot has a major Aim drawback but it can be offset by equipment or stat progression. Disabling Shot gives the Alpha an additional options to use against the aliens, specially for capturing them. Executioner turns it into a killer (and partially compensating for the Snap Shot penalty) and In The Zone can allows it to kill a dozen of enemies on a single turn.
Gunslinger can be used together with Executioner but it can only used with In The Zone once.
Their drawbacks are: the lack of protection/HPs when compared to other classes, which makes it challenging to use them in frontline roles; their lack of firepower at close range, despite the added damage to pistols from Gunslinger.

Sniper Beta (Sniper)

Rank	Ability	Sniper
Squaddie	Headshot Fire a shot with +30% critical chance and extra damage on critical hits based on the tech level of the sniper rifle. 2 turn cooldown.
Corporal	Squad Sight Allows firing at targets in any ally's sight radius.
Sergeant	Damn Good Ground +10 Aim and +10 Defense against enemies at lower elevation in addition to the usual elevation bonuses.
Lieutenant	Battle Scanner Scanning device, when thrown creates a new source of vision for 2 turns. Can only be used 2 times per battle.
Captain	Opportunist Eliminates the Aim penalty on reaction shots, and allows reaction shots to cause critical hits.
Major	Low Profile Makes partial cover count as full.
Colonel	Double Tap Allows both actions to be used for Standard Shot, Headshot, or Disable Shot, provided no moves were made. 1 turn cooldown.

Sniper Betas are true snipers, designed to stay afar from well chosen positions and drop targets at very long ranges.
Squad Sight gives them the ability to fire at any place with a clear line of sight while Opportunist turns them into deadly sentries and Double Tap doubles their damage output.
Battle Scanner can be used to recon distant areas, specially at mission start.
Their main drawback is their lack of protection and inadequate firepower at close range.

Support

Support Alpha (Medic/Scout)

Rank	Ability	Medic
Squaddie	Smoke Grenade Deploy a smoke grenade once per mission. The smoke confers +20 defense to all units, not just allies, and lasts during the enemy turn.
Corporal	Sprinter Allows the support to move 3 additional tiles.
Sergeant	Field Medic Allows medikits to be used 3 times per battle instead of once.
Lieutenant	Revive Allows Medikits to revive critically wounded Soldiers at 33% of maximum health instead of just stabilizing them.
Captain	Dense Smoke Smoke Grenades have increased area of effect and further increase units' Defense by 20.
Major	Deep Pockets Confers an additional item slot in inventory.
Colonel	Savior Medikits restore 4 more health per use.

The Alpha Support's primary role is as a medic but it can also be used as a scout, due to the Sprinter ability.
Alphas can be used as support units, healing and providing smoke cover.
They can also be used quite effectively as scouts, but they have less protection than other classes and if they are critically injured they can't be healed, unless there's a second Medikit still available.

Support Beta (Support)

Rank	Ability	Support
Squaddie	Smoke Grenade Deploy a smoke grenade once per mission. The smoke confers +20 defense to all units, not just allies, and lasts during the enemy turn.
Corporal	Covering Fire Allows reaction shot to trigger on enemy attacks, not just movement.
Sergeant	Smoke and Mirrors Allows 1 additional use of Smoke Grenade each mission.
Lieutenant	Rifle Suppression Fires a barrage that pins down a target, granting reaction fire against it and imposing a 30 penalty to aim.
Captain	Combat Drugs Smoke Grenades now contain powerful stimulants that grant +20 Will and +10% Critical Chance for all units in the cloud. (Also grants +20 Aim Bonus)
Major	Deep Pockets Confers an additional item slot in inventory.
Colonel	Sentinel Allows two reaction shots during Overwatch, instead of only one.

The Support Beta is can be used either in offensive or defensive roles, having a similar role to the Heavy Beta.
Smoke and Mirrors and Combat Drugs give it the ability to pump up twice a squad's stats inside the smoke cloud for two rounds.
Covering Fire, Suppression and Sentinel give it more Overwatch options/shots while also allowing it to suppress an enemy.
Its drawbacks include insuficient firepower against high level aliens plus Supports are one of the weakest human units and not built for trading shots with the aliens.