What are Defensive Buildings for?
There are two kinds of defensive structures - passive and active.
Passive defensive structures include Walls, Gates, Towers, and Improvements. All of these additions contribute to your Base's total defense bonus, granting all your defensive units additional combat effectiveness when fighting off attackers. This bonus will only be applied to defensive units currently garrisoned in your Base and outside of your Bunker.
Active defenses include Automated Gun Turrets and Artillery Emplacements. Unlike Walls, Gun Turrets and Artillery will actively participate in defensive battles just like one of your regular Units - unlike normal Units, when they're damaged they can be repaired and brought back online for free by you or by Friends as many times as needed, granting a considerable long-term advantage. Active defenses also contribute to your overall Defense Bonus. Defensive structures cannot be deployed to locations outside your Base.
Note: There is no difference between Gun Turrets and Artillery Turrets aside from their appearance.
Why do I need Improvements?
All Improvements help increase your Base's Defense Bonus. The more of these additions you have in your Base, the higher your Units' Defensive rating. Only Units actively defending your Base (not in the Bunker) will receive the Defense Bonus.
MARS Repair Vehicle
MARS Repair Vehicles are improvement items capable of automatically repairing all defensive Turrets, Artillery, and Improvised LZ in your Base.
MARS Repair Vehicles are activated automatically upon signing into the game, do not consume Resources, and cannot be damaged or destroyed.
Each MARS Repair Vehicles you install increases the rate of repair for the Improvised LZ, and all defensive emplacements in your Base by 5%. You may install a maximum of 5 MARS Repair Vehicles.
To install a MARS Repair Vehicle:
1. Go to your Base.
2. Click "Construction".
3. Open the "Improvements" tab and select the MARS Vehicle.
4. Select an area within your Base and begin construction.