Marines#
Marines never heal on their own.
Exosuits only repair through welders and MACs.
Aliens#
All aliens slowly regenerate when out of combat: every 2 s they heal 2% of their base max health (between 1 and 20). Out of combat means no damage dealt or taken for 3 s.
Fire halves alien healing (×0.5) while it burns. Heal spray can put the fire out.
Health or armor?#
Most of each hit lands on a marine's armor (until it runs out), but med packs and the armory restore health only; only welders and MACs restore armor. A marine who has been bitten is often full health with no armor after a med pack, which is why marines weld each other after every fight. See also Crush, which moves even more damage onto armor.
Healing limit#
To stop several healers making an alien unkillable, healing received is reduced once it passes 12% of max health within 1 s: anything above that is cut to 34%.
Structures#
- Alien structures do not heal on their own, the hive included. Only crags and heal spray repair them; maturing raises their maximum health and keeps the same health percentage, so a maturing structure gains a little. That is why a gorge on the hive matters so much in a siege (see Ink vs ARCs).
- Power nodes are rebuilt by welding or by building.