When Do Biters Attack?
Biters attack when:
- Pollution reaches their nest (they become angry)
- You destroy a nest (immediate retaliation)
- Evolution factor is high enough (time + pollution)
Peaceful mode: Even without biters attacking, you still need to clear nests to expand. Walls help protect your builders.
The Minimum Viable Defense
Step 1: Stone Wall (Priority 1)
Place stone walls in a rough circle around your base. 1 tile thick is enough for the first few hours.
Cheap: Stone walls cost only stone bricks
Effective: Biters cannot destroy stone walls quickly
Step 2: Gun Turrets (Priority 2)
Place gun turrets every 5-8 tiles along the wall. They need ammo (firearm magazines or piercing rounds).
| Turret Type | Ammo | DPS | Notes |
|---|---|---|---|
| Gun turret | Firearm magazine | Low | Early game only |
| Gun turret | Piercing rounds | Medium | Upgrade ASAP |
| Laser turret | Electricity | High | Mid-game power hungry |
Step 3: Ammo Management
Use steel chests next to each turret, fed by inserters from a central ammo belt.
Critical: If your turrets run out of ammo, they are just decoration. Set up a dedicated ammo production line early!
Pollution Management (Defense by Reducing Aggression)
Biters attack because of pollution. Reduce pollution = fewer attacks.
| Method | Effect |
|---|---|
| Efficiency module 1 in miners | Minus 30 percent pollution |
| Efficiency module 2 in labs | Minus 45 percent pollution |
| Solar panels | Zero pollution power |
| Burning excess wood | Plus plus pollution (don't do it) |
Defense Upgrade Path
The upgrade order as your factory grows:
Stone Wall right arrow Gun Turrets (firearm mags)
down arrow
Steel Wall right arrow Gun Turrets (piercing rounds)
down arrow
Laser Turrets (electricity powered, no ammo)
down arrow
Flame Turrets (area damage, fuel-based)
down arrow
Artillery Turrets (long range, explosive shells)
Next: Defense Guide Overview — all defense layers explained.