Overwatch (EU2012)
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 moves without any cover into their vision range during the enemy turn, albeit at a small aim penalty and without dealing critical hits.
Overwatch can serve two tactical proposes:
- To keep an enemy unit pinned down or risk a reaction shot
- To keep them from occupying key positions that allow them to flank your own units
- To ambush unseen enemy units as they walk into the soldier's field of vision
- To cover chokepoints such as corridors and flanks
- To wipe out activated aliens before they reach cover
Some class abilities alter or improve various aspects and properties of Overwatch. These include Rapid Reaction (Heavy), Squad Sight (Sniper), Opportunist (Sniper), Covering Fire (Support), and Sentinel (Support).
When overwatching be aware of what accuracy percentage you are likely to get. It is better to hunker down and double your defense bonus rather than risking a 20% shot. Especially early on with rookies with low accuracy and carrying weak weapons it isn't worth the risk.
Due to the aim penalty, overwatch can be more effectively used to "pin down" aliens while your squad maneuvers, rather than for direct damage. An aliens will never, or very rarely move if it sees an agent enter overwatch (this holds true for aliens under suppressing fire as well). This can be exploited to great effect: it allows you to move your agents into flanking positions, while at the same time preventing the aliens from doing the same to you. Please note that aliens that do NOT see the agent go into overwatch will still freely move, and will more than likely trigger the reaction shot. If all your squad's reaction shots are triggered, then the aliens will once again move freely, so care must be taken when setting up overwatch for this tactic.