Armoury

The Armoury is a ToG (Tons of Guns) tech building, which is an equivalent of the Workshop tier-wise.

Main use
Once the Armoury is built, it gives you access to Weapons, Flak and EMP Rocket, to the Munitions Plant and the Factory.

You generally want to place it at the start of the game, to get some Weapons or next tier tech fast.

Other info
Tech buildings are some of the most expensive buildings, but also the most expensive to repair. Because of their high HP, it takes a long time to repair, and because of their high cost, it takes a lot of metal/second to repair. In the end, it's extremely expensive.

Armoury is less used in forts games, because of its vertical shape, it's harder to fit in a fort. Some players even called this "tetris", trying to fit everything correctly.

As all tech buildings, it takes a lot of time to build so you can make defenses before your opponent has weapons.