Planetary defence are the structures built to protect the planet from enemy invasions. As they're attached to the surface of the planet, defense are not mobile nor removable by fleets, so you can't use them to raid.
You can find three main types of defense: turrets, missiles, and shield domes. Turrets provide cannons or projectiles to shoot the invaders' ships. They usually have a low armour and shielding. However, shield domes provide a great endurance to attacks, so they can absorb much more damage and give extra time to turrets and defensive fleets to shoot. Missiles can be used to attack players' defenses, but they can also be used to defend from oncoming missiles. The interplanetary missiles fired at your planet can be blocked with anti-ballistic missiles.
After combat, each defensive structure has a 70% chance of being rebuilt for free, unless it was destroyed by an Interplanetary Missile (in which case, it has no chance). Your defending fleet, however, will not be rebuilt. Destroyed ships from the defending fleet and the attacking fleet make a debris field. A Recycler can pick up the debris resources and add them to your resource pile.
The base time taken to construct a defense depends on the amount of metal and crystal the defense costs. Construction times are otherwise only reduced by Shipyards and Nanite Factories.
Unlike buildings and research, it is not possible to cancel the production of a defense (this is also the case with ships). Once resources are put into building a defense, those resources can never be retrieved again.
However, also unlike buildings, defenses don't take up any fields. This means you can build as many defenses as you please, provided you have the resources necessary.
- Missile Launcher
- Light Laser Turret
- Heavy Laser Turret
- Gauss Cannon
- Ion Cannon
- Plasma Cannon
- Small Shield Dome
- Large Shield Dome
- Atmospheric Shield
- Gravitons Canno
- Orbital Defence Platform