Every alien can carry one upgrade from each chamber type that the team has built. The strength of an upgrade depends on how many of that chamber exist (1, 2 or 3, see Upgrade chambers). Upgrades are free for skulks; other lifeforms pay an upgrade cost per upgrade when they evolve (Gorge 1, Lerk 3, Fade 5, Onos 8 res).
| Chamber | Defensive | Utility | Offensive |
|---|---|---|---|
 Shell (Crag Hive) | Carapace | Regeneration | Vampirism |
 Veil (Shade Hive) | Camouflage | Aura | Focus |
 Spur (Shift Hive) | Celerity | Adrenaline | Crush |
Shell upgrades#
Carapace#
Extra armor. The bonus grows with biomass and with the number of Shells: bonus = (base + per-biomass × biomass) × shells ÷ 3.
| Lifeform | Base armor | Carapace base bonus | per biomass | Armor at biomass 9, 3 Shells |
|---|---|---|---|---|
| Skulk | 10 | 5 | 1 | 24 |
| Gorge | 50 | 12 | 2 | 80 |
| Lerk | 30 | 12 | 1 | 51 |
| Fade | 80 | 20 | 2.5 | 122.5 |
| Onos | 450 | 50 | 20 | 680 |
Regeneration#
Replaces the innate alien healing with a stronger one. Every 2 s out of combat you heal 6% of your base max health (at least 6, at most 80), × shells ÷ 3. Without it, aliens heal 2% (between 1 and 20) per tick. Neither works while you are under fire.
Vampirism#
Each hit on a marine gives you an overshield worth a share of your max health (× shells). The share depends on the attack:
| Attack | Share per hit at 1 Shell |
|---|---|
| Skulk bite | 4.66% |
| Gorge spit | 2.67% |
| Lerk bite | 2% |
| Fade swipe | 3.33% |
| Fade stab | 6.67% |
| Onos gore | 1.83% |
Parasite, spikes and heal spray give nothing.
Veil upgrades#
Camouflage#
You fade out while still or moving slowly; moving fast makes you more visible. Attacking, taking damage or touching a marine reveals you briefly. More Veils make you cloak faster. Observatories and scans reveal camouflaged aliens.
Aura#
Shows enemy players within 10 m per Veil (10 / 20 / 30 m) through walls, as an icon over their position. The icon shows where a marine is, not how hurt they are (no health indicator).
Focus#
Your main attack hits harder but slower: up to +33% damage and 33% longer between attacks with 3 Veils (a third of that per Veil). Works on skulk bite, gorge spit (no slow), lerk bite, fade swipe and stab, and onos gore. The big win is breakpoints: a Focus skulk kills an A0 marine in 2 bites instead of 3.
Spur upgrades#
Celerity#
+1.5 m/s top speed at 3 Spurs (a third of that per Spur). It also raises the skulk's bunny-hop and wall-jump speed caps and the fade's blink speed.
Adrenaline#
Faster energy regeneration. Normally aliens regenerate 10 energy per second. With 3 Spurs, Adrenaline raises it to the lifeform's own rate (Skulk 27, Gorge 13, Lerk 13, Fade 15, Onos 15); with fewer Spurs it is in between.
Crush#
+7% per Spur. Against structures and exos it adds that much damage. Against marines it does not add damage; instead armor soaks a bigger share of each hit (70% normally, +7% per Spur), so marine armor is stripped faster. That rarely changes how many hits a kill takes (see the Crush columns in Hits to kill). Crush is mainly an anti-exo and anti-structure upgrade.
Which to pick?#
- Skulks: Carapace or Vampirism; Celerity; Aura or Focus.
- Lerks: Regeneration or Carapace; Adrenaline; Aura or Focus.
- Fades: Vampirism or Regeneration; Celerity or Adrenaline; Aura.
- Onos: Carapace or Regeneration; Celerity; Aura or Focus.
These are common picks, not rules. See Hits to kill to check what an upgrade changes.