Defense means keeping the Steam Core working as threats approach. Walls, units and energy networks must work together; an unsupplied turret is just another structure in the way.
Preserve a defensible route
The game requires a valid route between the Core and the territory boundary. If the blocked-path warning appears, reopen the route before the displayed countdown ends. Completely sealing the base can cause the colony to be lost.
Use walls to organize approaches and protect maintenance access. Test the route after installing doors, large machines or new floors: their occupied volume may close a passage that looked clear.
Follow the current defense tree
| Research | Required preparation |
|---|---|
| D1 | E1 and R1; opens early walls and Defense Robot manufacturing at the Workshop |
| D2 | D1 and E2; unlocks the Steam Turret, Metal Gate and metal walls |
| D3 | D2; opens the High-Pressure Weapon and high-pressure kits |
| D4 | D3 and E3; unlocks the Tesla Coil |
| D5 | D4 and E4; opens the Ether Robot |
The Steam Turret uses high pressure. Prepare a Pressurizer and verify the connection before nightfall. The Tesla Coil needs a supplied electrical network; its registered demand is 8 EU/s. Reserve generation capacity beyond what production machines consume.
Before, during and after an invasion
- Refill fuel and check defense networks. Inspect energy warnings and the condition of access routes.
- Recall exposed workers with PANIC!. Combat units remain outside that directive.
- Watch the direction of approaching threats. The campaign uses Rust, Forest, Quarry and Desert variants; consult their entries to compare characteristics.
- During the attack, maintain a path for your character and access to machines. Avoid an improvised closure that blocks the Core.
- Afterward, use the Repair Tool available after R2 and inspect routes before releasing workers.
The Ethereal Steam Veil changes the late game: while active and supplied at night, it prevents new spawns. It does not remove enemies already present.
Source notes
Assets/SteamPunkColony/Scripts/Gameplay/TechTree.cs:457— active defense progression.Assets/SteamPunkColony/Scripts/Gameplay/CraftingCatalog.cs:588— Steam Turret energy.Assets/SteamPunkColony/Scripts/Gameplay/ElectricityRuntime.cs:273— Tesla Coil demand.Assets/SteamPunkColony/Scripts/UI/GameLocalization.cs:1337— blocked Core route consequence.Assets/SteamPunkColony/Scripts/Gameplay/Agents.cs:12216— variants;:12340— Veil suppresses new spawns and preserves existing enemies.