Tactics | XCOM-2 Wiki

Tactics in XCOM 2 will vary from Mission to Mission and from squad to squad. This page is dedicated to various tactics that work well in "most" situations.

Tactics

• Be on the look out to flank your enemies, and watch your flanks.
• If an enemy is hiding behind a high cover and you can't kill it due to the Defense bonus, try landing a grenade to destroy the cover and let others shoot the flanked enemy to death. Be mindful, however, that certain cover elements (such as the metal columns in tunnel maps) cannot be destroyed by any means. 
• High percentage shots can and will miss - always try to have a backup plan.
• If you're starting an ambush, DO NOT put all of your squad to Overwatch; usually, not everyone is going to successfully land the shot, and on the enemy's turn (if any survived,) you'll end up defenseless. A soldier (preferably a Grenadier) equipped with a Flashbang Grenade can save your troops' lives, for example.
  • That said, Overwatch shots triggered during an ambush do not incur the penalties normally applied to them. This can be used a efficient way to hit enemies before they get to cover.
• Sometimes, it can be advantageous to set squadmates to Overwatch before exploring new areas. Always make sure, however, that most of your units have enough actions to react to a pod activation.
• Try to build a Flashbang Grenade as soon as possible. It can save your troops' lives, since it not only prevents enemies from using special abilities and lowers their Aim/Mobility but also cancels Mind Control, one of biggest threats in the early game.
• If your soldier is caught up in a flanked position, use Specialist's Aid Protocol and Smoke Grenade to raise his/her defenses.
• Invest in abilities with guaranteed chances to hit, such as Combat Protocol. They can be invaluable in situations where chances are against your squad, such as when an wounded enemy is behind full cover or when you need to unbound your soldier from the grasps of a Viper.
• After building the Shadow Chamber, you can see how many enemy units, and which types you'll encounter on the mission. Don't equip your soldiers with Dragon Rounds if you're up against robotic enemies. Same goes for organic enemies; they are immune to the effects of EMP Grenade and Bluescreen Rounds.
• Two Frags will destroy a vehicle immediately, which if aimed properly, can kill a full health Muton using it as a cover.
• An example of a well-rounded squad consists of a Grenadier, a Sharpshooter, two Rangers, and two Specialists: a hacker and a medic, since it provides a good mix of utility and damage.
  • However, XCOM allows for a variety of tactical choices and this shouldn't be taken as a perfect template. In a general sense, most squads should include cover removal tools, such as explosives, scouting characters for map intelligence and utility in the form of defense and healing oriented items/abilities. 
• Don't waste time trying to shoot turrets on roofs.  A single frag grenade can take them out since it destroys the structure below them.

General guidelines for scouting:

• While in concealment, prioritize approaching the objetive quickly and don't be afraid to double move in timed missions if the squad has clear line of sight over the terrain. 
• Consider going loud as soon as you spot the first enemy pod if you have a good opportunity to kill it. Completely stealthing most missions is effectively impossible without a Reaper due to how the A.I. is designed.
  • Being spotted on the enemy turn is highly dangerous since the A.I. may take actions immediately. Do not be overzealous with squad concealment.
• Rangers and Reapers remain concealed even when the squad has been revealed. If possible, attempt to hold on to their concealment for as long as possible - engaging enemy pods individually is the safest way to win any mission.

General tips for successful engagements: 

• In XCOM: Enemy Unknown and its sequel, enemies are distributed around the map in so called "pods". A pod contains a limited number of enemies and, once an unconcealed XCOM soldier gains line of sight over one of the enemies who compose them, that pod is said to be activated, meaning its members will take actions once the player's turn is over.
• The safest way to play vanilla XCOM is to activate as few enemies during your turn as possible while killing as many of these enemies before your turn ends. 
  • To achieve that, use concealment as often as you can and, in its absence, single move one soldier at a time, with one of them being the scout which the others will either follow if no enemies are seen or engage otherwise.
  • Higher difficulties, such as Legend, possess no limit to how many enemies may be activated at once. Combined with the other modifiers inherent to it, simultaneous activations can be catastrophic when playing on them.
  • Prioritize activated enemies according to the threat they'd pose should they be allowed to act. To do so, extrapolate their behavior based on the A.I. - for example:
    • Sectoids and ADVENT Priests are likely to use Psionic abilities in their turns, specially if no flanking opportunities present themselves. This makes them relatively low-threat enemies when isolated, since some of these abilities may be completely irrelevant for the engagement.
    • Most enemies with AOE abilities will use them if they can hit more than one XCOM operative, specially if they cannot flank and sometimes even if they do.
    • An ADVENT Shieldbearer will always use it shield in its turn if it hasn't yet.
  • Always take into account the enemy in question before using crowd control abilities - Flashbanging or setting alight a Psionic enemy can be a terrible move since, then, they won't be able to use their (often harmless) abilities and instead will shoot.
  • Non-lethal damage is pointless unless Red Fog is enabled. A 2HP enemy is as deadly as he was at full health - do not expose a soldier to deal non-lethal damage if you don't have to.

Enemy specific insight:

• When targeted by melee attacks of any kind, including Rend and Strike, Mutons have a high chance of counterattacking, negating all damage, stabbing the attacking unit and sometimes stunning it. Mutons can instantly execute any stunned enemy within melee range.
• Enemies with multiple actions points such as Gatekeepers, Sectopods and The Chosen will lose action points but still act during their turn if Frozen.
• Melee only enemies, such as the Lost and the Andromedon's shell, can be neutered by gaining elevation and then blocking the climbing tile with a soldier.
• A Specter will always use Shadowbound as its first action if able. This makes them predictable and harmless if killed immediately on the following turn.
• Gatekeepers will prioritize raising as many Psi Zombies as possible as its first action. 
• The Chosen Warlock can be nearly completely countered by the inexpensive Mindshield.
• Buried Chryssalid will be revealed by Scanning Protocol and Battle Scanners. They are also susceptible to Bladestorm combined with Overwatch.