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Strategy

Alien Deployment

There are four types of aliens present in the game: Commanders, Soldiers, Secondaries and Roaming. Commanders will only appear on UFO missions, Soldiers can appear on Abductions, Council and UFO missions, and Secondaries will appear in UFO and Terror Site missions. All of these three types can also be present in Storyline missions. The type of aliens apply only to Drones and those are only deployed as escorts to larger robotic units or by themselves during the Alien Base mission.

Soldiers (type 0)

Commanders (type 1)

Secondaries (type 2)

Roaming (type 3)

Drone

Pod Composition

The aliens deploy their units in pods of 1-3 aliens, usually made of the same species. In the case of some specific aliens their pods can contain 1 unit of the pod species type, plus 1-2 escorts from another alien species:

Berserkers (with Mutons as escorts)
Cyberdiscs (Drones)
Mechtoids (Sectoids or Sectoid Commanders)
Sectopods (Drones)
Ethereals (Muton Elites)

The composition and number of aliens on each pod depend on 3 main factors: the difficulty level, the type of mission and the month.

Abductions and Terror Sites

On the case of Abductions the difficulty level of the mission displayed on the Mission Control selection screen will also determine the number of aliens present during tactical missions.

Aliens on Abductions will consist only of Soldier types, while on Terror Sites the pods will be only of Secondary alien types.

	Mission Difficulty	Total Pods	Total Aliens	Total Pods	Total Aliens	Total Pods	Total Aliens	Total Pods	Total Aliens
'	'	Easy		Normal		Classic		Impossible
Abductions	1st Mission	2	4	2	4	3	6	3	8
	Easy	2	4	2	4	2	4	N/A	N/A
	Normal	3	6	3	6	3	6	N/A	N/A
	Difficult	4	8	4	8	4	8	4	10
	Very Difficult	4	10	4	10	4	10	4	12
Terror Site	1st Mission	3	6	3	6	3	6	3	9
	Regular	3	8	4	10	5	12	5	15

Council missions

Council missions introduce another type of alien deployment besides pods, which is dynamic aliens, or the aliens who fall down from the sky during the mission. Assault type missions will not contain any dynamic aliens.

Council	Total Pods	Pod Aliens	Dynamic Aliens	Total Aliens	Total Pods	Pod Aliens	Dynamic Aliens	Total Aliens	Total Pods	Pod Aliens	Dynamic Aliens	Total Aliens	Total Pods	Pod Aliens	Dynamic Aliens	Total Aliens
	Easy				Normal				Classic				Impossible
March	3	3	2	5	3	3	2	5	3	4	3	7	3	7	4	11
April	4	4	2	6	4	4	2	6	4	5	4	9	4	8	6	14
May	4	6	2	8	4	6	2	8	4	6	5	11	4	10	6	16
June	4	8	3	11	4	8	3	11	4	10	6	16	4	10	6	16
July	4	9	4	13	4	9	4	13	4	12	6	18	4	12	6	16
August	4	10	6	16	4	10	6	16

UFOs

On UFO missions the game will introduce the Commander type aliens, deployed as a single Pod (usually located at the bridge of the UFO, although its location can vary.

	Total Pods	Pod Aliens	Bridge Pod	Total Pods	Pod Aliens	Bridge Pod	Total Pods	Pod Aliens	Bridge Pod	Total Pods	Pod Aliens	Bridge Pod
Difficulty	Easy			Normal			Classic			Impossible
Small Scout Crashed	3 Soldier	4	1-3	3 Soldier	4	1-3	3 Soldier	4	1-3	3 Soldier	6	1-3
Small Scout Landed	3 Soldier	9	1-3	3 Soldier	9	1-3	3 Soldier	9	1-3	3 Soldier	12	1-3
Large Scout Crashed	4 Soldier	7-9	1-3	4 Soldier	7-9	1-3	4 Soldier	7-9	1-3	4 Soldier		1-3
Large Scout Landed	4 Soldier	10	1-3	4 Soldier	10	1-3	4 Soldier	10	1-3	4 Soldier	12	1-3
Abductor Crashed	3 Soldier 1 Secondary	9	2-3	3 Soldier 1 Secondary	9	2-3	3 Soldier 1 Secondary	9	2-3	3 Soldier 1 Secondary	9	2-3
Abductor Landed	3 Soldier 1 Secondary	12	2-3	3 Soldier 1 Secondary	12	2-3	3 Soldier 1 Secondary	12	2-3	3 Soldier 1 Secondary	12	2-3
Supply Crashed	4 Soldier 3 Secondary	9-15	2-3	4 Soldier 3 Secondary	9-15	2-3	4 Soldier 3 Secondary	9-15	2-3	4 Soldier 3 Secondary	10-18	2-3
Supply Landed	4 Soldier 3 Secondary	16	2-3	4 Soldier 3 Secondary	16	2-3	4 Soldier 3 Secondary	16	2-3	4 Soldier 3 Secondary	21	2-3
Battleship	7 Soldier 4 Secondary	20	2-3	7 Soldier 4 Secondary	20	2-3	7 Soldier 4 Secondary	20	2-3	7 Soldier 4 Secondary	26	2-3
Overseer

Pod Species

When choosing between the alien species the game will create a pool of potential alien species to assign to pods each month where each species will have a certain weight or probability of being chosen. On the next month the game will add new species to the pool and recalculate their probabilities of being chosen. There are defined limits on the number of pods of specific species that can be encountered during a mission. On the Impossible difficulty levels the limits seem to be disregarded (to be confirmed).

Pod Mission Assignment

Abduction missions will only have present type 0 (Soldier) aliens, while Terror Sites will only have type 2 (Secondary) aliens. Council missions will consist mainly of type 1 aliens, with several exceptions on Slingshot and EW. Small and Large Scouts UFOs will have only type 0 pods, along with a type 1 pod of alien UFO commanders. Larger UFOs and the alien base will have pods of both early types plus a single type 1 pod consisting of the alien craft's command crew. The Tutorials (Regular and Meld), along with the first Abductions, Terror Site and UFO missions have predetermined alien pod numbers and species.

Soldier Management

Use the first 3 missions to bring all the 12 initial soldiers and reveal their classes.
The focus is on building a poll of soldiers - it should be around 10-12 soldiers being rotated on missions, plus a number of replacements.
A basic setup is to have 2-3 officers of each class, depending on personal preferences - your favorite build(s) for that class and his/her replacement, plus an alternative build for more specialized missions.
To get the Squad Size increase, you can get later a Sergeant as a reward in an abduction mission.
Try to get as soldiers as rewards during Abduction missions (although you may lose countries) - money and resources are easy to get, high rank soldiers take a lot of time to build up. Even if you have already 2 officers from that class
Usually the distribution of classes will not be balanced. Use Abduction missions to make up with any shortfalls.

1) Maps 2) Type and number of aliens.

The first criteria is if XCOM or the aliens are capable of killing their opponents with 1 shot. At the beginning the aliens will have the upper hand, specially in Classic/Impossible but that will keep changing back and forward as XCOM deploys new tech and the aliens bring more races. There's something of a ratio: if you're facing 3 lesser opponents or 2 similar ones or 1 superior alien you're outnumbered and your soldiers can be severely injured or killed.

With this in mind you may face three types of scenarios everytime you'll go on an Abduction/Terror/UFO missions. Council missions are predictable since you'll be facing always Sectoids or Thin Men.

Class Builds
Class/Type	Corporal	Sergeant	Lieutenant	Captain	Colonel	Notes
Support (Medic)	Sprinter Covering Fire	Field Medic	Revive	Dense Smoke Combat Drugs	Savior
Support (Scout)	Sprinter	Smoke and Mirrors	Rifle Suppression	Dense Smoke	Sentinel
Support (Rifleman)	Covering Fire	Field Medic Smoke and Mirrors	Rifle Suppression	Dense Smoke Combat Drugs	Sentinel
Assault (Charger)	Aggression	Close and Personal	Rapid Fire	Bring 'Em On	Killer Instinct
Assault (Flanker)	Tactical Sense	Lightning Reflexes	Rapid Fire Flush	Close Combat Specialist	Resilience
Assault (Rifleman)	Tactical Sense	Lightning Reflexes Close And Personal	Rapid Fire Flush	Bring 'Em On	Resilience
Sniper	Squad Sight	Gunslinger Damn Good Ground	Disabling Shot	Opportunist	Double Tap In The Zone
Sniper (Scout)	Snap Shot	Gunslinger Damn Good Ground	Battle Scanner	Executioner	Double Tap In The Zone
Heavy (Support)	Holo-Targeting	Shredder Rocket	HEAT Ammo	Grenadier	Rocketeer	Demolition/Squad Support
Heavy (Rifleman)	Bullet Swarm	Suppression	Rapid Reaction	Danger Zone	Mayhem	Requires a lot of ammo.
Heavy (Antiarmor)	Bullet Swarm	Shredder Rocket	HEAT Ammo	Danger Zone	Rocketeer
Heavy (Grenadier)	Bullet Swarm	Shredder Rocket	HEAT Ammo	Grenadier	Mayhem
'

Class Builds

Each class has been designed with two main builds, Alpha (left side) and Beta (right side). Although experienced players will design soldiers according to their own preferences, this article will focus on the basic builds available to each class.

Class Builds

Normal Weapons Kill Table

Weapon	Base Damage	Crit Damage	Critical Chance	Maximum Damage (Base + Crit)?	Sectoid Thin Man Outsider Drone	Floater	Muton Chryssalid	Zombie Sectoid Commander	Heavy Floater	Muton Elite	Cyberdisk	Bezerker Ethereal	Sectopod
					3	4	8	10	12	14	16	20	30
Pistol	1	1	0	2
Laser Pistol Laser Pistol (I)	2	3	10 30	5	CRIT	CRIT
Laser Pistol (I & III)	3	3	30	6	BASE	CRIT
Plasma Pistol Assault Rifle Plasma Pistol (I)	3	4	0 10 20	7	BASE	CRIT
Plasma Pistol (I & III)	4	4	20	8	BASE	BASE	CRIT
LMG Sniper Rifle Shotgun	4	6	0 25 20	10	BASE	BASE	CRIT	CRIT
Laser Rifle Plasma Light Rifle	5	7	10	12	BASE	BASE	BASE	CRIT	CRIT
Heavy Laser Laser Sniper Rifle Laser Scatter	6	9	10 30 20	15	BASE	BASE	BASE	CRIT	CRIT	CRIT
Plasma Rifle	7	10	10	17	BASE	BASE	BASE	CRIT	CRIT	CRIT	CRIT
Heavy Plasma Plasma Sniper Rifle Alloy Cannon	9	13	10 35 20	22	BASE	BASE	BASE	BASE	CRIT	CRIT	CRIT	CRIT

Classic Weapons Kill Table

Weapon	Base Damage	Crit Damage	Critical Chance	Maximum Damage (Base + Crit)?	Sectoid	Thin Man Floater	Outsider Drone	Chryssalid	Muton Zombie	Heavy Floater Muton Elite Sectoid Commander	Cyberdisk Bezerker Ethereal	Sectopod
					3	4	5	8	10	14	20	30
Pistol	1	1	0	2
Laser Pistol Laser Pistol (I)	2	3	10 30	5	CRIT	CRIT	CRIT
Laser Pistol (I & III)	3	3	30	6	BASE	CRIT	CRIT
Plasma Pistol Assault Rifle Plasma Pistol (I)	3	4	0 10 20	7	BASE	CRIT	CRIT
Plasma Pistol (I & III)	4	4	20	8	BASE	BASE	CRIT	CRIT
LMG Sniper Rifle Shotgun	4	6	0 25 20	10	BASE	BASE	CRIT	CRIT	CRIT
Laser Rifle Plasma Light Rifle	5	7	10	12	BASE	BASE	BASE	CRIT	CRIT
Heavy Laser Laser Sniper Rifle Laser Scatter	6	9	10 30 20	15	BASE	BASE	BASE	CRIT	CRIT
Plasma Rifle	7	10	10	17	BASE	BASE	BASE	CRIT	CRIT	CRIT
Heavy Plasma Plasma Sniper Rifle Alloy Cannon	9	13	10 35 20	22	BASE	BASE	BASE	BASE	CRIT	CRIT	CRIT

Impossible Weapons Kill Table

Weapon	Base Damage	Crit Damage	Critical Chance	Maximum Damage (Base + Crit)?	Sectoid	Outsider	Thin Man Floater	Drone	Chryssalid	Muton Zombie	Sectoid Commander	Heavy Floater	Muton Elite	Cyberdisk	Bezerker Ethereal	Sectopod
					4	5	6	7	8	10	14	16	18	20	25	30
Pistol	1	1	0	2
Laser Pistol Laser Pistol (I)	2	3	10 30	5	CRIT	CRIT	CRIT
Laser Pistol (I & III)	3	3	30	6	CRIT	CRIT	CRIT
Plasma Pistol Assault Rifle Plasma Pistol (I)	3	4	0 10 20	7	CRIT	CRIT	CRIT	CRIT
Plasma Pistol (I & III)	4	4	20	8	BASE	CRIT	CRIT	CRIT	CRIT
LMG Sniper Rifle Shotgun	4	6	0 25 20	10	BASE	BASE	CRIT	CRIT	CRIT
Laser Rifle Plasma Light Rifle	5	7	10	12	BASE	BASE	BASE	CRIT	CRIT
Heavy Laser Laser Sniper Rifle Laser Scatter	6	9	10 30 20	15	BASE	BASE	BASE	CRIT	CRIT
Plasma Rifle	7	10	10	17	BASE	BASE	BASE	CRIT	CRIT	CRIT
Heavy Plasma Plasma Sniper Rifle Alloy Cannon	9	13	10 35 20	22	BASE	BASE	BASE	BASE	CRIT	CRIT	CRIT

Notes on Damage

BASE = alien can be killed with 1 shot; CRIT = alien requires either 2 normal shots or 1 critical hit with usually maximum critical damage.
Regarding the different numbers seen in the Barracks info and the actual game values, one theory is that the damage range can vary, i.e. a weapon listed with a 9 damage can vary between 8 and 10 and you see the maximum damage before firing.
How the critical damage is applied isn't clear/proven. The model above assumes that there are separate rolls, 1 for normal damage, then it is added the value of another roll for critical damage.
The other model is that the maximum damage for a critical hit is the one listed but that doesn't fit with actual combat results, since I've seen Heavy Plasmas dealing 16 damage to a flanked soldier.

Discussion

Apologies for intruding, but are we sure that Critical damage completely stacks with Base damage? So far as I've seen, critical damage OVERLAPS base damage, IE, a critical hit uses the higher "Critical damage" number in the randomizer, instead of the Baze Damage number.

I appreciate the feedback. Good question - my current impression is that damage is dealt in two rolls, one for hit (base damage) and a 2nd one which seems to be randomized within the critical damage ability. I've made kills that also support this model, like 1 Alloy Cannon shot killing an undamaged Muton Elite that has been flanked. Hobbes 18:51, 6 November 2012 (EST)

Also, the Base Damage, as found elsewhere, seems to be able to be modified by one (and possibly more)in either direction. So Guaranteed kills may not quite count unless the damage is high enough that even -1 is still enough to one-shot. (IE, 4 base damage LMG, -1=3: Still enough for a Sectoid) Arrow Quivershaft 18:41, 6 November 2012 (EST)

I've checked the damage on my current Classic game. From what I've researched there's no change to it on the difficulty levels. Which makes a lot of sense since it's a lot easier to learn the game if you always play with the same weapon stats. Hobbes 18:51, 6 November 2012 (EST)

What I mean is that it randomizes damage on a hit, not by difficulty, just a bit of basic randomizing so that things aren't always the same. Sorry for being unclear. Arrow Quivershaft 02:23, 7 November 2012 (EST)

I've switched my game settings to show the alien's health bars (so far I was developing this model based on the results from hits to my soldiers. Yesterday I saw an Alloy Cannon dealing 22 damage points to a Sectopod so the basic assumption, game damage = (base damage roll) + (critical damage roll) is correct. The question is how the critical damage roll is distributed: on Base Damage the deviation seems to be slight (the values displayed on the Armory correspond to average base damage, while on missions the damage displayed while firing is the maximum base damage. On critical damage the distribution of results seems to follow a growing pattern: the bigger the critical damage inflicted the lesser the chance you'll get that result.Hobbes 08:57, 14 November 2012 (EST)

Regarding zombie HP, I edited it because I saw 10hp zombie in impossible, but was a bug like 3hp thin man in impossible. 14 is right :) - Moyang

Alien Types Distribution Table

Mission	Sectoid	Thin Man	Outsider	Drone	Floater	Muton	Chryssalid	Sectoid Commander	Heavy Floater	Muton Elite	Cyberdisk	Bezerker	Ethereal	Sectopod
Abductions	YES	YES	NO	YES	YES	YES	YES	NO	YES	?	YES	YES	NO	?
Terror Site	NO	NO	NO	YES	YES	YES	YES	NO	YES	NO	YES	YES	NO	YES
UFO Crash Site	YES	YES	YES	YES	YES	YES	YES	YES	YES	YES	YES	YES	YES	YES
UFO Landing Site	YES	YES	YES	YES	YES	YES	YES	YES	YES	YES	YES	YES	YES	YES
Council	YES	YES	NO	NO	NO	NO	NO	YES	NO	NO	NO	NO	NO	NO

Alien Numbers Distribution Table

Mission	# Alien Packs	# Aliens	Alien Species
Abductions	?	2-12*	ALL
Terror Site	?	6-12*	YES
Crashed Small Scout	3	5-8	YES
Crashed Large Scout	?	8-12	YES
Crashed Abductor	?	12?	YES
Crashed Supply Barge	?	?	YES
Crashed Battleship	?	23	YES
Crashed Overseer	?	8-12?	YES
Landed Small Scout	4	6-10	YES
Landed Large Scout	?	8-12?	YES
Landed Abductor	?	23	YES
Landed Supply Barge	?	?	YES
Council	?	?	YES

Game Files Info

XCOMGAME.UPK

AI Behaviour

Moving vs static packs

Moving packs will roam the battlefield until spotting XCOM or civilian units.
Static packs will be hunkered down and waiting for enemy units to be seen.
Ambush packs are aliens that will appear active but on Overwatch.
The AI will 'teleport' either type of packs from one map location to the other, if they are still 'unactivated' (haven't seen XCOM units)

Active vs passive aliens

Active aliens are alerted to XCOM's presence and will take action immediately upon sight.
Aliens can be activated in 3 ways:
- By spotting XCOM units - the run for cover animation will be played - this requires for the XCOM unit to move into a visible square. However due to Line of Sight mechanics it is possible to spot a group of passive aliens while moving diagonally without activating them.
- By being activated by other already active aliens - the individual alien seems to emit a specific sound that can activate passive packs without the 'run for cover' animation.
- By firing and hitting any of the aliens with indirect fire by using Rocket Launchers, Squad Sight snipers, etc.

Swarming

The AI seems to respond to scouts by pulling back some units to 'alert' other alien packs and/or 'teleporting' aliens closer to the position of last seen XCOM units. If those aliens are already activated this will result in very nasty surprises for XCOM.
This can be visible on the amount of packs that are teleported and activated in terror/abduction missions in the first turns.

Tutorial/Council/Temple Ship Missions

All packs are static or ambush
Active aliens will not activate passive packs
No teleporting

Abduction/UFOs/Alien Base Missions

Moving/Static packs
Active aliens will not activate passive packs
Teleporting

Terror Missions

Moving/Static packs
Active aliens can activate passive packs
Teleporting

Damage Values

Assault Damage Values

Weapon	Base Damage	Crit Damage
Pistol Pistol (III) Laser Pistol	1	2
Pistol Pistol (III) Assault Rifle Laser Pistol Laser Pistol (III) Plasma Pistol	2	3
Pistol (III) Assault Rifle Shotgun Laser Pistol Laser Pistol (III) Plasma Pistol Plasma Pistol (III)	3	4
Assault Rifle Shotgun Laser Pistol (III) Laser Rifle Plasma Pistol Plasma Pistol (III) Plasma Light Rifle	4	6
Shotgun Laser Rifle Laser Scatter Plasma Pistol (III) Plasma Light Rifle	5	7
Laser Rifle Laser Scatter Plasma Light Rifle Plasma Rifle	6	9
Laser Scatter Plasma Rifle	7	10
Plasma Rifle Alloy Cannon	8	12
Alloy Cannon	9	13
Alloy Cannon	10	15

Heavy Damage Values

Weapon	Base Damage	Crit Damage
LMG	3	4
LMG	4	6
LMG Heavy Laser	5	7
Rocket Launcher Heavy Laser	6	9
Heavy Laser	7	10
Heavy Plasma	8	12
Heavy Plasma Blaster Launcher	9	13
Heavy Plasma	10	15

Sniper Damage Values

Weapon	Base Damage	Crit Damage	Headshot	Gunslinger
Pistol Pistol (III) Laser Pistol	1	2	NA	+2
Pistol Pistol (III) Laser Pistol Laser Pistol (III) Plasma Pistol	2	3	NA	+2
Pistol (III) Sniper Rifle Laser Pistol Laser Pistol (III) Plasma Pistol Plasma Pistol (III)	3	4	+2	+2
Sniper Rifle Laser Pistol (III) Plasma Pistol Plasma Pistol (III)	4	6	+2	+2
Sniper Rifle Laser Sniper Rifle Plasma Pistol (III)	5	7	+2 +4	+2
Laser Sniper Rifle	6	9	+4	NA
Laser Sniper Rifle	7	10	+4	NA
Plasma Sniper Rifle	8	12	+6	NA
Plasma Sniper Rifle	9	13	+6	NA
Plasma Sniper Rifle	10	15	+6	NA

Support Damage Values

Weapon	Base Damage	Crit Damage	Base (Shredder)	Crit (Shredder)
Pistol Pistol (III) Laser Pistol	1	2	1	2
Pistol Pistol (III) Assault Rifle Laser Pistol Laser Pistol (III) Plasma Pistol	2	3	2	4
Pistol (III) Assault Rifle Laser Pistol Laser Pistol (III) Plasma Pistol Plasma Pistol (III)	3	4	4	5
Assault Rifle Laser Pistol (III) Laser Rifle Plasma Pistol Plasma Pistol (III) Plasma Light Rifle	4	6	5	7
Laser Rifle Plasma Pistol (III) Plasma Light Rifle	5	7	6	9
Laser Rifle' Plasma Light Rifle Plasma Rifle	6	9	8	12
Plasma Rifle	7	10	9	13
Plasma Rifle	8	12	10	16

Classes Tables

KEYCHART

Left Side Abilities	Right Side Abilities	Additional Shot	Improves Reaction	Extra Movement	Additional Equipment	Change Unit Aim	Decrease Enemy Aim	Increase Damage Given	Decrease Damage Taken

Assault

Assault Ability/Rank Tree
	Action	Aim	Damage			Notes
						Allows firing after the 2nd action 2 turn cooldown
						+5 Defense for every enemy in sight (max +20)
						+10% Critical chance per enemy on sight (max 30%)
						First reaction shot fired at this unit always misses
						Bonus declines with distance from the target
						Allows a shot that forces target to leave cover Shot has +30 Aim and deals fixed 4 points damage
						Allows to fire 2 shots with 1 Action Reduced accuracy (-15 Aim)
						Gives a single shot enemy that approaches within 4 tiles Applies to both the player and the enemy's turn
						+1 Damage for each enemy within the squad's vision (max 5)
						Heavier armor increases the bonus
						Immunity to Critical Hits
						Activating Run & Gun will give the unit +50% in Critical Damage

Heavy

Heavy Ability/Rank Tree
	Action	Aim	Damage			Notes

						Allows for two shots, or to move after firing
						Gives +10 Aim to any squad members firing at the same enemy
						Shredder Rocket deals 4 points damage (6 Blaster Launcher)

Sniper

Sniper Ability/Rank Tree
	Action	Aim	Damage			Notes
						3 turn cooldown


						Only applies to pistols
						Adds upon other aiming bonuses, including flying with Archangel armor

						Can be used combined with Squad Sight

						The normal Overwatch aim penalty is -30

						Can only be used once with pistols Can be combined with Snap Shot 2 turn cooldown
						Can be used with pistols Cannot be combined with Snap Shot

Support

Support Ability/Rank Tree
	Action	Aim	Damage			Notes

Squad Roles

There are 3 squad roles that each soldier can assume during a fight to achieve its tactical objectives, regardless of their class and/or abilities. They are:

Maneuver - the capacity for the squad to move and reach favorable positions during your turn;
- Move/Dash - usual game actions;
- This role involves detecting the enemy (scouting), retreating and/or outflanking it;
- It also involves dislodging enemies from their own positions during your turn.
Fire - to weaken and/or eliminate enemy targets during your turn;
Fire/Throw - usual game actions.
- This role also involves removing enemy cover or boosting up a soldier's Aim/Critical Chance stats.
Security - to prevent enemy actions during your and their turns.
- Cover/Overwatch/Suppress/Hunker Down - usual game actions;
- Security also involves healing wounds since they prevent KIAs.

The 3 roles are tightly interlinked together. A soldier moving to outflank an alien will increase squad security since it may force it to withdrawal from its position.

General vs Specialized Soldiers

Some soldiers are more inclined for specific squad roles than others due to their stats, class/abilities and equipment carried. The trade-off when selecting a soldier is between generality (for instance, a Rookie) and specialization (i.e. a Colonel). The more specialization, the better a soldier will be able to perform that specific role but if it is absent due to injury or incapacitated/killed, then your game play may be affected. In contrast, a more generic soldier will not be as effective in a specific role but it can more easily be replaced.

The choice between both types of soldier also reflects itself on the choice of class abilities at each rank. Each class is designed to favor 1 or more roles and the individual abilities reflect that design. Some abilities may also apply to two roles.