Mortar
The simplest defense: cheap, made of metal only and available right away – and the terror of unprotected transports and probes.

The mortar is the first defense installation you can build. It only costs metal and is ready quickly. On its own it is weak, but in large numbers it keeps raiders with small fleets away.
- + Metal only – no kryptonite, no spice.
- + Bonus damage against the Small transport ship, the Large transport ship and the Spy probe: raids with unprotected freighters get expensive.
- – Low attack and a weak shield. The Warship and the Stealth bomber even deal bonus damage to it.
Background
The mortar is specifically designed for the defense against small and large transport ships and spy probes. It is very effective in defending against these ships however not overly effective against attacks from larger ships.