Gameplay Mechanics (EU2012)

Action System

In Enemy Unknown 2012 the gameplay has been streamlined regarding the previous games, with the intention use a simpler system than the one used by the predecessor of the original game. Thus, the Time Units have been removed and replaced instead with an action system, where each unit can perform 2 Actions during its turn.

Move and Fire

A normal turn will have the unit doing Move + Fire or just take 1 Action. The soldier's class and abilities also determine the options available for the 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 in a turn.
• A unit's turn automatically ends after the unit:

1. Performs any other 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 can Fire + Fire.
  • Run & Gun - Assault can Dash + Fire but not Dash + Equipment.
  • Snap Shot - Sniper can Move and Fire with a Sniper Rifle.

List of Actions

These are general actions that can be perform 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 Ghost armor. Doesn't cost as an action.
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.
Aim?	Increase Aim for a number of turns. (unconfirmed)
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 small (?how much?) 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

Equip	Change the current item with another one.
Heal Wound	Use Medikit to heal Health Points.
Stabilize/Revive	Use Medikit to stop bleeding and/or wake up an injured soldier.
Combat Stim	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	Use a scanning device to increase your vision.

Moral

• Squad members are effected by moral 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.

Environments

• 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 move 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 increasing 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. From the demo, it seems that you can get down from a roof anywhere.

• There are weather effects in the game as well as day/night however they have no effect on game play.

Tactics

• 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.

• 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 (though do not seem to 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).