Arsenal

The arsenal is used to produce resonators, a critical component for researching artillery upgrades and improving machine gun and mortar emplacements, and can be built when you reach player level 17. Resonators are constructed out of ionites and ammunition. At level 1, you can produce 1 resonator for the cost of 200 ionites and 200 ammunition; subsequent upgrades reduce the cost to 100 of each resource per resonator, and allow for the production of more at a time (although with a longer time per individual resonator). Above level 6, the per-resonator cost increases again, but the speed of production gets more efficient.

The gallery below shows the arsenal at all different levels.

Each level of the Arsenal unlocks a larger batch of resonators that can be produced at one time, as shown in the table below:

Your journal has this to say about your arsenal: After capturing the Osterberg fortress, Karl Gustav repeatedly pointed out to Commander Grant that the Resistance needed to build the Arsenal as soon as possible and start the resonators production.

''He never was tired of explaining how resonators work: feeding the device with boosted frequency will lead to resonance in the fine structures of the ionite lattice and the formation of the electromagnetic pulse which is needed for detonating the capsule of the large-caliber shells. This means that resonators are very important for creating or upgrading the support shells. Even if your artillery itself is powerful, accurate and has a long-range, it remains just a pile of metal without shells. Don't forget that, commander.''