# The Hierarchy of Reasoning
The Hierarchy of Reasoning is about answering the following question: What the hell is this thing I am looking at. It is a hierarchy because people don’t look at something and download the relevant information in one giant chunk. We pull it in, piece by piece, and slowly build our Mental ModelThe player's vision in their mind for how things work. Often this will be different than how it actually works. for what it is and how it functions. There are a great many resources that will discuss the science behind AffordanceThe properties of an in-game object or mechanic that imply or communicate how the player should best use it. An axe implies, or 'affords' a downward motion to the attack, while a small dagger 'affords' a stabbing motion. and models, but speaking practically, it helps to think of it as a three tiered process.
# The Tiers of Reason
- Primary Clue
- Secondary Clue
- Tertiary Clue
The Hierarchy of Reasoning is a visual language for speaking to the player. Each level in the hierarchy is about asking that single question–what am I looking at–yet receiving ever more detailed answers.
Think of the hierarchy like an excavation dig.
- You brush away some dirt, and in so doing receive hints (a peak of white bone)
- You brush away some more dirt and it begins to take form (it’s definitely a skeleton)
- Finally, after you brush away the last of the dirt, it reveals its nature (holy shit a t-rex).
Do not think, however, that The Hierarchy of Reasoning must be defined visually. You can define them through sound just as you can though color. Imagine a game where you play an English assassin, for example. You have been sent to the German consulate, and your task is to take out their ambassador. Given this, the sound of two Germans having a conversation is a clear read that you have a threat nearby. So what exactly defines the parts and pieces that make up the hierarchy?
# The Tools of Reason
The tools of observation are independent of the hierarchy. You use tools to build your hierarchy, to paint it, and you can paint in both broad strokes and fine details.
There are four major tools you can use to build your hierarchy.
- Presence – This sounds like silhouette, but it’s more than that. It’s about that feeling you get when you look at something, which is about archetypes. Is it covered in spikes, or is it pudgy; is it made of metal, or is it made of fur; is it human, or just pretending; why the hell are its insides on the outside. You can be subtle or you can be overt, but presence is important.
- Motion – This is as much about standing still, which we’d call stance, as it is about locomotion. Do yourself a favor and pick up a few BBC specials like Planet Earth, if you haven’t already, and watch how animals move. It’s important to build that library in your head of how different things move in the world. It will help you to define what you want, and motion is certainly important.
- Color – A big one, obviously, but don’t limit yourself to the basic look. Consider, too, all the modality changes you’re going to have. Red means threat, for example, so having a robot’s little eye go from green to red, upon spotting the player, is a simple yet powerful color key to our subconscious.
- Sound – You can paint in both broad and fine strokes with sound just as easily as you can with any of the other tools — remember our example above with the German consulate — and you should not forget to use it. Seriously, don’t forget sound.
# When to use
- You have multiple enemies in your cast from the same group or faction, who have meaningfully different gameplay, and you need to be sure the player can evaluate them quickly and correctly
- Your players are frequently dying to a particular enemy.
- You are trying to analyze the Combat Roles in your game.
# When not to use
- You want more variation in your enemies.
# An Example
Let’s take an example from vanilla World of Warcraft. Imagine you are a horde rogue and out of the corner of your eye you spot some movement:
- Primary – It has a short and stocky presence: dwarf.
- Secondary – Its clothing is made of cloth: priest.
- Tertiary – They are surrounded in dark particles: shadow priest.
It seems simple — as do most well executed things — but this simplicity belies the masterful execution. At every step in the hierarchy they give you a little bit more information, and, in most cases, you can define not just the CLASS you are facing, but also the specific talent SPEC you are facing. When you consider that there are numerous races, and each race can be several classes, and each class can spec different ways, yet the player is still able to understand what he is looking at… that is premier execution of the Hierarchy of Reasoning.
Let’s study another example. Say I’m making a game with both humans and robots. For differentiation I make the decision that all Robots are going to be triple jointed in the legs. That is going to affect the motion and presence of every single member of the robot cast. That is HUGE. This choice gives a clear primary clue indicator to every single robot in the game.
Additionally, let’s say the robot faction has two bipedal enemies: a generic soldier and a captain soldier. The captain, to further differentiate him, includes a cool spinning command orb in his chest. Here we have added some motion to the captain solder that will probably be missed on a primary clue, but will be picked up when the player begins to focus on him.
Motion, as you can see, works on multiple levels, not just primary, and the same is true for all the tools. It’s important to understand that these tools are independent of the hierarchy that you are trying to build.
I know it feels that I’m straying a little far from system design here, but you have to understand that you can’t decouple this knowledge from the systems you are building. And, most certainly, I don’t think you should take this knowledge and go running to your concept artists and animators demanding changes. Don’t be an ass. This knowledge allows you to start a conversation. One that, hopefully, has a mutual footing you both share.