Army

The Army tab is unlocked once the first Castle/Shooting Range is built. In the army tab, depending on if you built Shooting Range and/or Castle, you can buy Archers from Shooting Range and Swordsmen from Castles.

 The base cost of Archers is   5Qi and gives 1 Battle Power Per Second (BPs)

 The base cost of Swordsmen is   59.1Qi and gives 1 Battle Power Per Second (BPs)

Each level of Shooting Range adds +1 Additional Reward from monsters.

Each level of Castle increases BPs by 1.

City Walls gives you access to Garrisons. Each level of City Walls adds a boost to Garrisons which increases BPs by 1 for every 10 Garrison owned. Unfortunately there are no Garrisons for Archers.

Garrisons will increase Fatigue (Army version of Discontent) for each Garrison built.