Confined fractal charge launchers are defensive structures used to support Blasters.
Mortars require 50 build packets [equal most expensive] before coming online. They also require 30 ammunition packets to fill their reserves, and use 4 per charge launched.
Mortars fire explosive fractal charges that devastate Creeper in the blast radius. The charges can damage any depth of Creeper; Mortars are more effective against deep Creeper, and in fact downright inefficient against shallow concentrations. Because of that, they will auto-target the deepest Creeper in range. They are also capable of shoooting over walls allowing them to destroy creeper eating through walls or on higher planes than them.
Mortars, like all defensive structures, can withstand limited exposure to Creeper, and will self-repair if connected to the network and not being damaged.