Gameplay Mechanics (EU2012)

From UFOpaedia
Jump to navigation Jump to search

Sub Sections

Chance to Hit

  • Aim, Defence, and a number of other bonuses and penalties all combine to determine the final chance that a shot will hit.


  • In combat, soldiers and aliens can take cover behind objects in the environment to lower their chance of being hit by enemy fire. Cover is taken automatically as the soldier moves through the environment. While in cover the soldier gains a defensive bonus against enemy attacks unless the enemy has flanked the soldier.

Critical Hits

  • In many cases, shots may have a chance to incur up to around 150% of their usual damage.

Critical Wounds

  • After sustaining more damage than the Soldiers Health Points (HPs), the Soldier will either become critically wounded or die.


  • Current theories on how the weapon damage works.


  • A flanked target is indicated with a yellow shield. This target receives no benefits from cover and chances to score a critical hit against it are increased by 50%.


  • A soldier or alien with a remaining action can enter Overwatch (default hotkey Y). This ends the soldier's turn, but allows them to shoot at the first enemy that enters their overwatch range during the enemy turn, albeit at a small penalty (aim penalty/no critical hits).


  • How movement is translated into actual game squares (1.625 points = 1 square)-


  • Its purpose is to degrade the enemy's ability to fire and maneuver.

Action System

In Enemy Unknown 2012 the gameplay has been simplified when compared to previous titles, possibly with the intention to attract a wider console audience. Thus, Time Units have been removed and replaced with a two-part action system, where each unit can perform 2 Actions during its turn.

Moving and Firing

In a single turn, a soldier has two Action points. The soldier's class and abilities determine the options available for their 1st and 2nd Actions. The following rules are a brief summary of how Actions work:

  • A unit may perform 1 or 2 Actions each turn.
  • Some actions (firing Sniper Rifle or Rocket Launcher) may only be performed as the 1st Action and consume both Action points.
  • A unit's turn automatically ends after the unit:
  1. Performs any action other than Move on its 1st Action.
  2. Performs a 2nd Action after moving as the 1st Action.
  • The following Abilities change the above rules:
    • Bullet Swarm - Heavy can Fire + Fire/Move/Surpress/Overwatch.
    • Double Tap - Sniper can Fire + Fire (Can also use Headshot or Disabling shot for either but not both due to cool down).
    • Run & Gun - Assault can Dash + Fire but not Dash + Equipment.
    • Snap Shot - Sniper can Move and Fire with a Sniper Rifle at reduced accuracy.

List of Actions

These are general actions that can be performed by your soldiers during the fight, depending on their Equipment and Class.

Movement Actions
Action Description
Move Walk
Dash Fast movement. Provides defensive bonus against enemy reaction fire.
Grapple Move and use Grapple hook use to reach a higher position.
Hunker Down Doubles cover bonus & provides immunity to critical hits, but reduces sight radius.
Toggle Flight Activates flight mode on Archangel armor. Doesn't cost as an action point.
Ascend/ Descend Go up/down one level while flying. Doesn't cost as an action.
Weapon Actions
Action Description
Fire Shoot weapon at enemy/area.
4 types of weapon shots: Standard, Headshot, Disabling and Free.
Grenade Throw grenade.
Stun Can incapacitate targets for capture, easier if target's health is reduced.
Suppress Fires at the area around the target to reduce its aim.
Overwatch Takes a shot at the next enemy that moves through that unit's line of sight. A 20% Aim penalty applies.
Reload Spend a full action to reload weapon.
Psionic Perform a series of mental and physical attacks using Psionics.
Other Equipment Actions
Heal Wound Use Medikit to heal Health Points.
Stabilize/Revive Use Medikit to stop bleeding and/or revive an injured soldier.
Combat Stim Use Medikit to temporarily increase a soldier's Will and reduce damage taken.
Ghost Makes the soldier invisible for 1 turn or until attacking. Doesn't cost as an action.
Battle Scanner Throw a scanning device to increase your vision.


  • Both your soldiers and the aliens are able to sense one another's presence by detecting any noise produced by the other side as a result of movement or firing.


  • Squad members are affected by morale and can panic on the battlefield, moving and firing uncontrollably on friend and foe alike. Losing squad members increases this chance while higher-ranked squad members and Officer Training Upgrades reduce this chance.


  • Everything is destructible with the exception of floors/ceilings and bringing down entire buildings.
  • Explosions can start fires which can spread each turn. These prevent movement across them but that can be countered with special armor.
  • Entering buildings is much more dynamic than in previous games. Squad members can break through windows to enter buildings, kick down doors or quietly open them in standing on either side of the door frame. The two former options increase the chance enemies will hear you and come to investigate.
  • Roofs and elevated positions can be utilized for better line of sight and squad tactics. Beyond traditional stairs and ladders, squad members can use drain pipes or armor upgrades to grapple or jet pack to higher elevations. You can get down from a roof anywhere, (unless there's something in the way) so long as the drop is less than three elevation.
  • There are weather effects in the game as well as day/night however they have no effect on game play.


  • Overwatch: Overwatch only allows a shot against the first unit spotted. For example, if you put a soldier on overwatch and they fire at the first enemy to move, any subsequent enemies moving through that soldier's line-of-sight will not be fired upon. The same applies to aliens overwatching against you. For example, you could use a high-HP unit (e.g., SHIV) to draw enemy reaction fire and then follow-up with a more vulnerable unit's move. This could also work against you if you're being flanked by multiple units the same turn. Take notice that overwatch has reduced chance to hit, cannot crit and only happens if unit moves within your sight range, so if you stop as soon as you get into overwatching unit's view, overwatch will not trigger.
  • Alien encounters: Sometimes aliens are setup to spawn at a given point on the map, such that they do not move until discovered by one of your units. Upon discovery, the aliens interrupt your squad's turn and immediately move (but do not take action/attack). They tend to move relative to the unit discovering them and either attack that position (e.g., aggressive Floaters) or take cover against that unit's position (e.g., Sectoids, Thin Men). Therefore, if you're on a mission where time/turns don't matter (e.g., mission brief indicates no civilians; no countdown timer for mission objectives) you should move units one movement each at a time. In other words, don't immediately dash a unit as far as possible, especially without overwatch protection. Cycle through your whole squad giving each unit their first move before deciding whether to move each again or take action. Otherwise, you may encounter a group of aliens that can quickly flank that forward unit while the rest of your squad is out of moves/actions. Also, you may hinder your ability to purposefully flush the aliens toward a choke point, bunch them up in range of a specific unit (e.g., Heavy who can still fire his rocket, in Sniper LOS), or limit them to an area of the map with poor cover (e.g., explodable vehicles, half-cover).
  • Taking advantage of alien squad script: Aliens can never attack you unless you "awaken" them first (a cinematic has played where camera shows a bunch of aliens) and when alien squad is provoked, they never take any offensive action or overwatch, only move. This means that you are never in danger of receiving any damage unless you have an unfinished alien alive from a provoked pack on the map. Therefore, there is not much incentive to stay in cover when there are no "provoked" aliens alive - rather, having suitable cover in range of 1 movement is enough. Taking advantage of this fact, you can beat enemy in tactical quite easily and without casualties. If you keep your people together (you can even stand in the open and on adjacent tiles), and advance slowly, every time going on overwatch with all your soldiers, you can make it so that aliens pop up on their turn (all except immobile squads, which are rare). This will make them trigger your overwatch, and then run to cover, and give you a full turn to either take them down or retreat into cover and setup an overwatch ambush. When having 2 squad sight snipers on a team, this usually lets you take down any alien squad before they even get a chance to fire a shot at you, and if they live, you retreat into cover which is beyond their line of sight, so that your snipers can squad-sight-overwatch enemy advance, which will finish them off. Take opportunist on snipers to have better hit chance on overwatch and lightning reflexes on assault to discover remaining enemies (letting snipers take care of them) without getting damage.
  • Do not provoke more aliens: Each extra tile you reveal (get sight on) can have next alien pack waiting. Provoking them when you are not ready can prove fatal. This means that for example, if you've just finished fighting cryssalids and have only one soldier with action points remaining, never move him in a position where he'd uncover new area, because if you happen to find new aliens there, they'll get to attack you before you can do something about it. However, ending turn, you either get aliens on their turn (they do their free movement, you get your turn to attack them) or dont (again, you have full action points to do something).
  • The changes in the action system are most notable when fighting Chryssalids. While fundamentally the same as their counterparts in the original, they are significantly less dangerous this time around because of the two action system. Instead of moving to a position where they can reach you next turn, they will dash up to your squad and end their turn standing right next to you, allowing them to be easily picked off.

EU2012 Badge XCOM: Enemy Unknown: Gameplay Mechanics
Action SystemMovementChance to HitCoverCritical HitsCritical WoundsDamageFlankingOverwatchSuppression