|“||Beam attack that causes high damage and grants free Overwatch. If the Sectopod does not move, Cannon Fire can be used twice (against different enemies).||”|
– In-Game Description, XCOM: Enemy Unknown
Cannon Fire is an extremely devastating attack in both damage output (up to 2 shots at 9-11 damage per shot with a 10% Critical Chance (Classic/Impossible) for 15-16 damage) and the fact that it does area effect damage (AoE) in a 2 square radius (not applicable to Enemy Within), which can spell disaster for tightly clustered soldiers.
A missed Cannon Fire attack can still prove dangerous as there is a high chance of it taking out the target's cover, leaving it exposed to other enemies, the Sectopod's Overwatch or a second Cannon Fire if the target's the only enemy within its sight radius; the Overwatch uses a secondary top-mounted plasma cannon that inflicts 10 damage.
- The Sectopod can damage itself using Cannon Fire if a soldier is standing two tiles or less away from it.
- In XCOM: Enemy Within, Cannon Fire no longer deals AoE damage, making this tactic no longer viable.
- If the Sectopod uses Cannon Fire as a first action and does something else in the second action such as moving or preparing a Cluster Bomb attack, the free Overwatch is disabled.