|“||Confers +10% critical chance per enemy in sight (max +30%).||”|
– In-Game Description, XCOM: Enemy Unknown
- Aggression's bonus fully stacked is +30%. When combined with a shotgun (+20%) on a flank (+50%), this results in 100% critical hit chance (except against Hardened enemies). At 100% the player can plan the turn around having the crit, making some risky attacks a sure bet and a decisive victory.
- Aggression's bonus critical chance is always at least 10%, so that, combined with Close and Personal, a rifle will have a guaranteed critical hit in a point-blank flanking shot. Normally, only with a shotgun can you thus plan on a critical. — This no longer works with the reworked Close and Personal in XCOM: Enemy Within.
- Aggression's bonus is potentially extremely valuable for clearing melee packs, where it is often one turn, one volley, kill-or-be-killed.
- Aggression aids in overcoming critical-chance reduction on enemies with the Hardened property, such as Sectopods, Ethereals, and Cyberdiscs.
- If suppression builds are taken for Heavies and Supports, it may be more advantegous to take Aggression since many targets will be marked for death but not killed until the following turn, meaning an Assault will more frequently have full stacks of Aggression for their flanks. Those builds, the Heavies' in particular, are generally weaker than their alternatives and Aggression alone does not justify taking them.
- Aggression rarely stacks to 30%. Moving up with more than one alien alive and in sight is often risky since as the Assault can potentially activate more aliens as they charge in, resulting in the Assault getting overrun. Also, due to the possibility of front-line fighters missing their targets and leaving the Assault compromised and surrounded, the prudent Assault generally moves up last, after all other shots have been decided; thus, a lot of the aliens providing the Aggression bonuses might be killed. On the other hand, the player can decide to hold back on guaranteed kill actions (such as explosives) until Aggression Assaults have fired to preserve their bonus.