Defense installations (also known as Defense or Def) are units built permanently on a planet or moon to defend against attacking fleets. They are constructed in the Shipyard and cannot be canceled once building has commenced.
For defense in battles, your own ships, allied fleets in orbit, as well as built defense installations (guns and shield domes) are taken into account. The defense installations fire automatically.
Anti-Ballistic Missiles (also A-Raks) are also counted as defense, but are used exclusively to destroy enemy Interplanetary Missiles (also IRaks or IPR), which in turn can only be used against defense installations.
Unlike buildings, defense installations do not take up fields on the planet. Unlike fleets, they cannot be moved and thus cannot be saved.
| Unit | Costs | Values | Rapidfire | |||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Metal | Crystal | Deuterium | Structure | Shield | Attack | Cruiser | Destroyer | Bomber | Deathstar | |
| Rocket Launcher | 2,000 | 0 | 0 | 2,000 | 20 | 80 | 10 | 1 | 20 | 200 |
| Light Laser | 1,500 | 500 | 0 | 2,000 | 25 | 100 | 1 | 10 | 20 | 200 |
| Heavy Laser | 6,000 | 2,000 | 0 | 8,000 | 100 | 250 | 1 | 1 | 10 | 100 |
| Ion Cannon | 5,000 | 3,000 | 0 | 8,000 | 500 | 150 | 1 | 1 | 10 | 100 |
| Gauss Cannon | 20,000 | 15,000 | 2,000 | 35,000 | 200 | 1,100 | 1 | 1 | 5 | 50 |
| Plasma Turret | 50,000 | 50,000 | 30,000 | 100,000 | 300 | 3,000 | 1 | 1 | 5 | 1 |
| Small Shield Dome | 10,000 | 10,000 | 0 | 20,000 | 2,000 | 1 | 1 | 1 | 1 | 1 |
| Large Shield Dome | 50,000 | 50,000 | 0 | 100,000 | 10,000 | 1 | 1 | 1 | 1 | 1 |
Listed here are both the primary and secondary requirements. The latter are highlighted in yellow.
| Unit | Building | Research & Lab Levels | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Robotics Factory | Shipyard | Energy Technology | Laser Technology | Shield Technology | Weapons Technology | Ion Technology | Plasma Technology | Research Lab | |
| Rocket Launcher | 2 | 1 | - | - | - | - | - | - | - |
| Light Laser | 2 | 2 | 2 | 3 | - | - | - | - | 1 |
| Heavy Laser | 2 | 4 | 3 | 6 | - | - | - | - | 1 |
| Ion Cannon | 2 | 4 | 4 | 5 | - | - | 4 | - | 4 |
| Gauss Cannon | 2 | 6 | 6 | - | 1 | 3 | - | - | 6 |
| Plasma Turret | 2 | 8 | 8 | 10 | - | 7 | - | 5 | 4 |
| Small Shield Dome | 2 | 1 | - | - | 2 | - | - | - | 6 |
| Large Shield Dome | 2 | 6 | - | - | 6 | - | - | - | |