Season 1: Virus, Strongholds & Cities
How infection stacks and Virus Resistance work, how curing helps your alliance, and the rules for capturing Strongholds and Cities.
Virus infection
Fighting infected enemies gives you infection stacks (0–100). The more you carry, the worse the penalties:
| Stacks | Penalty |
|---|---|
| 1+ | A troop becomes seriously injured every few minutes |
| 20+ | Lower damage dealt (up to −20%) |
| 40+ | More casualties (up to +10%) |
| 60+ | You pick up even more infection when marching |
| 80+ | You can infect enemies even when you lose |
Some enemies always infect, whatever your resistance (they show a purple "+1 virus" icon). Acid Rain weather also adds stacks.
Curing
Allies can cure you with the green syringe. Each cure removes a stack, costs Immune Protein, and gives the curer Gene Fragments. Curing each other is one of the best things an alliance can do this season.
Virus Resistance
Every seasonal enemy needs a minimum resistance. Below it, your damage collapses: guides show a 2,000-point gap cutting damage by more than 90%. Raise it through the Virus Research Institute. The Weekly Pass adds a little more.
Gene Fragments
Fragments I–III drop from zombies, Doom Elites and radar, and IV–VI come mainly from curing allies. Genetic Recombination turns them into Mutant Crystal (you start with 10 charges and gain one every 2 hours, up to 30).
Strongholds
- Your alliance's first capture must be a level 1 Stronghold.
- Up to 2 captures per day. Each new one must touch one you already own.
- You can hold 3, plus more for each City you hold.
- A captured Stronghold gets 36 hours of protection.
Cities and Influence
- Declaring on a City needs an adjacent Stronghold. Up to 2 declarations a day, one war at a time.
- Hold up to 4 cities in your warzone and 4 in others.
- Each City gives your alliance Influence, from 100k (level 1) to 1M (level 6). Influence decides season rewards.
- From week 4, City wars can only be declared on set war days.
Common mistakes
- Rallying Doom Elites with low resistance.
- Spreading resources across all three Military Bases.
- Capturing random Strongholds instead of building a connected path.
- Treating seasonal buildings as permanent. They vanish at season end.
Sources
Compiled from community guides (last checked October 2026). Season details changed between servers and patches, so trust the in-game Season screen if something differs.