The Rat mostly relies on taxes to support his war funds and trades excess wood and stone once his humble economy is developed.
The Rat uses cheap, unarmored units in abundance and he attempts to steamroll the enemy with small attacks. His harassing groups consist of men-at-arms and conscripts, forming up to a dozen units per squad, and these teams attempt to break down farms and other outlying buildings.
Early on and frequently thereafter, the Rat sends out a sizeable force to lay "siege" on the enemy castle. Additionally to men-at-arms and conscripts, he also sends some archers for ranged support and constructs mantlets, later catapults against structures.
The Rat has several designs, with most of them using single-thickness walls and a gatehouse (curtain or regular). He keeps a light bodyguard team of conscripts, men-at-arms and archers around him, as well as a small taskforce of archers as a last resort. He also puts single units on the walls and the barracks, leaving them in a very vulnerable position.