The ICs are meant to be a quick way to compare characters and what their focus is. Many games use a “Class” system, like the Fighter, Thief, Cleric and Wizard. Typically the Fighter kills stuff (or stands around and gets hit, depending on your game), the Thief sneaks and disarms traps, the Cleric heals everybody and the Wizard does massive damage to everything in sight. Okay, that's fine to a point – the problem is that it's stereotyping. What about the smart fighter who excels at tactics and leadership? Or the war-priest who flies into a divine fury and slaughters the enemies of the faith? Or the con-man, who doesn't bother learning how to pick a lock because he just talks the owner into opening it? Or the wizard who is what the word's actually derived from, wise and knowledgeable? I could go on, but I hope this illustrates the problem with classes in many games: they limit freedom to create the kind of character you want to play, instead forcing you to play a stereotype.
TB tries to combat this by instead focusing on what your character does, with the IC system. The ICs are active, they are how you approach the world and what you like to do. There are 8 Intention Categories:
Labor (LBR) – doing work with your own hands, brains, or with other living beings is covered under Labor. Beyond basic physical labor this IC covers- sports, games, surveyors, logistics (knowing how to get the right tools to the right place at the right time) and other “white-collar” activities too.
Technical (TEC) – operating machines, computers, and whatever other devices all go here. Repairing, creating and modifying machines is also a part of this IC.
Knowledge (KNW) – the Knowledge IC is all about perception and understanding. What you can see, and how well you can understand what you see go here. This also covers how to hide and deceive as well.
Warfare (WAR) – in this case we mean Warfare to be direct, personal combat to harm or disable another being (as well as avoiding said harm). Blowing up a building is actually Technical, so is working a siege engine. Using the weapons on a vehicle is Direction, which covers vehicles and such [though, I do debate changing that and making the piloting DIR and the shooting WAR and working on-board sensors or computers or such TEC -CJ].
Direction (DIR) – movement, of oneself or by a vehicle, and navigation, these are the Direction IC. If it's about going from point A to point B then it's here.
Holistic (HOL) – Holistic is all about actions that directly relate to other living beings – like teaching or healing.
Environmental (ENV) – no man is an island, the world is all around each of us; and the Environmental IC is about how to deal with it. From building shelter, to finding food and dealing with animals - ENV covers everything "wilderness" related.
Interpersonal (INP) – not only are we surrounded by the world, but we are also surrounded by our fellow beings, which is where the Interpersonal IC comes in to play. Anything dealing with relationships between people goes here.