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Chapter 3. The Game Feel Model of Interactivity

Chapter 3. The Game Feel Model of Interactivity

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FIGURE



3.1 The model of interactivity brings together all the elements of the the gamer, the game and the world around him or her.



THE HUMAN PROCESSOR



knowledge: generalizations, ideas, concepts and misconceptions about the nature

of the world. All of these things are integrated into the perceptual field as they are

experienced.

The avatar is the player’s instrument within the game world, both for perception

and for expression. The movement of the avatar provides indirect insight into the

nature of the game world the same way our own hands may touch and probe and

noodle things around in order to experience them while our eyes and ears observe

the results. Perception requires action, as we’ve said, and all perception of a game

world must pass through the avatar.

With those three elements in mind, let’s step through Figure 3.1 and try to “bring

alive” the active process of game feel. Remember, this whole thing is happening at

a cycle time of around 240 ms, four or five times per second. Let’s start with the

human processor—the player.



The Human Processor

The human process is marked at “1” in Figure 3.1. Stimulus comes in through

the eyes, ears, fingers and proprioceptive senses. It is perceived at a cycle time

between 50 and 200 ms, depending on individual and circumstance. If two stimuli

are perceived within the same perceptual cycle, they appear fused, as with multiple

frames of an animation fusing into a single, moving character. If an action passes

out through the motor processor and the response is perceived in the same perceptual frame, there is a strong bias toward experiencing action and response as causal

(“My action caused this result”).

If this is an ongoing process, where perception, action and contemplation of the

same object happen in rapid succession over and over again, the experience is one

of control fusion—through my actions, I feel I am controlling something external to

me. This is what enables us to pick things up and move them, to throw and catch

things, and to generally interact skillfully with our immediate bodily surroundings.

When this process of ongoing control is able to flow uninterrupted and the

intent being served is more complicated than a single, simple action (grabbing

a muffin, for example) then we have a correction cycle, which happens around

240 ms and which is, at its core, the experience of game feel. As this process is running, the perceptual field is in the background coloring, ordering and assigning meaning to all new experiences. As soon as the experience happens, it is incorporated into

the perceptual field, expanding it. Skills are built, memories are formed, life is lived.



Muscles

Marked at “2” in Figure 3.1, the impulses from the human processor flow out

into the real world. The muscles of the hand execute the orders handed down by

the motor process, which has in turn been directed by the cognitive process. In



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CHAPTER THREE • THE GAME FEEL MODEL OF INTERACTIVITY



addition, the hand provides tactile and proprioceptive feedback to the perceptual

processor, the “megaphone for your thumbs” mentioned in the Chapter 1 section on

game feel as proprioception.



Input Device

The input device is marked at “3” in Figure 3.1. The input device is the player’s

organ of expression to the computer. All intent passes through the filter of the input

device before it can be interpreted by the system and used to update the state of the

computer’s model of the game’s reality, which is different from the player’s. The

motivation and experience of the player are more complicated than this in many

ways, but if the goal is to better understand the pieces of game feel that are malleable to the game designer, it’s convenient to think in these simplified terms. The

player has a particular intent at a given moment in time, and he or she expresses

that intent to the system via the input device. Whatever the input device is, it has

affordances and constraints. It will lend itself to controlling certain kinds of motion

more readily than others and has its own physical feel and character which will

ultimately affect the experience of game feel as perceived by the player.



The Computer

The computer is “4” in Figure 3.1. In one sense, the computer does its own perceptual, cognitive and motor processing. It accepts input at a certain rate, thinks

about it for a certain amount of time, and then responds, sending signals to its output devices. As with the human processors, the computer has a cycle time for this

whole endeavor. In the case of the computer, though, the response needs to happen

quickly enough for the player to perceive the response as instantaneous—within

one perceptual cycle (as little as 50 ms) of receiving input from the player.

For game feel to occur uninterrupted, input from the player’s muscles needs to

travel through the controller, be processed and come back as changes in pixels and

sounds before one entire cycle of the player’s perceptual processor has finished. The

computer needs to perform its half of the cycle faster than the player can perceive. If

this occurs, the player will see the series of incrementally changed visual frames as

a single moving object and will feel it reacting immediately to the input. The player

will readily interpret a cause and effect relationship, and the impression of control

is complete.



The Game World

The game world is marked “5” Figure 3.1. For our purposes, the game world exists

primarily in the player’s mind. There is also an internal representation of the game

world that exists in the computer, one which is more precise and mathematical than



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THE SENSES



the rich, expressive world experienced by the player. But a game system is designed

to output to an experience in the mind of the player. For the player, the output

devices are a window into the game world, and the avatar acts as a proxy within

that world. The player perceives the game world actively, through the “body” of

the avatar. Experiencing game feel is feeling out the game world, making additional

distinctions, and learning skills, concepts, and generalizations that make coping

with the unique world easier.

This is essentially the same process we undergo in our everyday lives. A game

world slots itself into the player’s action → perception → cognition cycle, replacing the physical world’s roles of accepting input and returning feedback. A game

world is simpler, easier to understand, and has clear, finite goals. This makes learning game skills faster, easier to measure, and, in many ways, more appealing than

real-world skills.



Output Devices

Marked at “6” in Figure 3.1 is the output device. The output devices, which may

include a monitor, speakers, controller’s rumble motors, haptic feedback device and

so on, are the player’s window into the game world. The monitor and speakers are

where the processing of the computer reaches reality. They are the computer’s organs

of expression to the player. The completed processes have resulted in an updated

system state for the computer, and it sends visual, aural and tactile feedback out

through its various channels into the world and, as we looked at in Chapter 1, the

position of the hands or other body parts on the input device offers the player proprioceptive feedback which can be reconciled with what’s happening on the screen

or coming through the speakers. Moving my thumb this far moves the character too

fast, so I subconsciously ease off the thumbstick by a millimeter or two.



The Senses

The loop is complete at the player’s sense, marked “7” in Figure 3.1. The senses

take in the updated state of the game world. The eyes, ears and hands (both tactile

and proprioceptive senses) perceive the new, changed state of the game’s reality

and pass them along to the perceptual processor. The cycle, having taken less than

half a second, is complete. The motions are amplified into the game world but still

have a real-world position that’s being perceived by the hands via the proprioceptive sense.

I’m keeping the Model Human Processor and meshing it with the perceptual

field. In my model, the perceptual field is fused with the perceptual and cognitive

processors, being at once a filter for new perceptual information, a framework in

which to slot it, and an ever-expanding reference library which contains not only

information about the meaning to assign each new stimulus but your schematic

diagrams of your world and everything in it.



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CHAPTER THREE • THE GAME FEEL MODEL OF INTERACTIVITY



The Player’s Intent

To complete our model, we need to account for intent. On one level, it’s an interesting question: where does intent come from? What motivates us to do what we

do? This question is perhaps more satisfying as applied to game worlds because

it can be answered definitively. Intent in a game world is designed by a game’s

creator; we don’t have to wonder at its origins, divine or otherwise. As for real-world

intention, French Philosopher Maurice Merleau-Ponty thinks that people have an

“in-born intentionality towards the world.” To say: “we’re born with it,’” though,

seems like a bit of a cop-out.

Maslow has some more interesting things to say about the nature of human

motivation with his pyramid of wants (see Figure 3.2). At the bottom are things like

satisfying your basic physical needs for food, shelter and warmth. Moving up, you

find security, love, self-esteem and, finally, self-actualization. The idea is that at any

time, if one of the lower rungs is unsatisfied, consciousness dips down to that base

level until that need is sated. People are constantly trying to reach higher and higher

on the pyramid, striving for creative satisfaction and whatnot. Sims, it seems, have

a hard time getting above the toilet level.

The pyramid fits with how Snygg and Combs incorporate intentionality and

motivation into their perceptual field. They envision a “perceptual self”—the vision

of yourself that exists as part of your own perceptual field. This is a cool concept, as

it seems to explain things like those self-immolating Tibetan monks from the Rage

Against the Machine album cover. A person can do things that don’t seem to serve

his or her body very well—lighting oneself on fire being one possible example—

but which enhance the perceptual self. You see yourself as a martyr, dying for a



3.2 Maslow’s hierarchy of needs starts with the basic physiological needs and

moves upward to self-actualization.



FIGURE



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SUMMARY



cause greater than yourself. Thus your own self-image, the embodied qualities of

yourself as you perceive you, is enhanced. And made more crispy.

Whatever the origin of human motivation is in reality, though, it is true that

part of game design is crafting goals, implicit or explicit, to motivate action in game

worlds. This is one of the dark arts of game design—creating meaningful, compelling intent from a seemingly arbitrary collection of abstracted variables. Think,

for example, of the coins in Super Mario 64. Ask yourself: if you didn’t get a star

for collecting 100 coins or if they did not restore Mario’s health, would you bother

collecting them? No, of course not. These are the arbitrary relationships between

abstract variables that give coins meaning in the game world of Mario 64. The star

itself is given meaning only by being rare and powerful, one of only 120 in the

whole game, each of which is a clear, measurable step toward unlocking the entirety

of the game’s levels, the (explicit) goal of defeating Bowser or the (implicit) goal of

collecting all the stars.

This is one of the most appealing aspects of video games for many players.

A game world’s logic is simple, easy to understand, and provides clear incentives,

rewards and feedback for effort invested. It’s safer than the chaotic and arbitrary

nature of everyday life. It’s comforting. In many cases, it rewards mediocrity or

at least makes it ignorable. Whether this is good or bad is a different question, but

it is worth noting that most game worlds do in fact have in-born intentionality, and

it’s the game designer who creates it.



Summary

The game feel model of interactivity offers a comprehensive picture of how game

feel occurs as a process. Each element involved in the process—the human processor, human muscles, input device, the computer, the game world, output devices,

the senses and the player’s intent—is necessary to keep the cycle running.

1. The human processor—where perception and thinking happen and motor

instructions are created.

2. Muscles—The motor instructions are executed as muscle movements.

3. Input device—The muscle movements are translated into a language the computer understands.

4. The computer—Where all processing happens, including integration of input

with the current state of the game world.

5. The game world—The computer’s internal model of the game’s reality.

6. Output devices—The updated game state is output into a form the player can

understand.

7. Senses—The player perceives the updated state through sights, sounds, touch,

and proprioception.



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CHAPTER THREE • THE GAME FEEL MODEL OF INTERACTIVITY



The player’s side of things does not change because of the fixed properties of

human perception, which limits the game designer’s area of influence. On the computer side of things, a designer is unlikely to have a role in creating the input device,

the computer or the output devices. The game designer’s palette, then, is contained

within steps 4 through 6.

Examining all the pieces in a cohesive model, we can finally make a firm delineation between games that have game feel and those that don’t. The model provides

a framework for understanding where things might be improved in a particular

design, and a foundation for creating game feel from scratch.



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FOUR

CHAPTER

Mechanics of

Game Feel

To wrap up our section on defining game feel, let’s apply all the ideas from Chapters

1, 2 and 3 to some specific games. To do this, we’ll return to our three-part definition of game feel: real-time control, simulated space and polish. The overall question to be answered is where a game fits on the diagram (Figure 4.1).

This breaks down, once again, into three questions:

1. Does it have real-time control?

2. Does it have simulated space?

3. Does it have polish?



FIGURE



4.1 Types of game feel: we want to put every game somewhere on the diagram.



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CHAPTER FOUR • MECHANICS OF GAME FEEL



From our model, we have measurable thresholds for real-time control to test

against:





10 frames per second. The images are displayed at a rate faster than one cycle of

the human perceptual processor, which will be 50 to 200 ms. Therefore, images

displayed at a rate at or above a rate of 10 frames per second will appear fused

into motion, and 20 frames per second or higher is necessary for a smooth

motion. In the case of a game, this is not a series of linear frames played back in

sequence but a series of states generated in response to input.







Response time of 100 ms or less. The game’s response to input happens within

one perceptual cycle (50 to 200 ms) of the player’s action, fusing into a sense of

causality and instantaneous response.







A continuous feedback loop. The game provides a continuous, unbroken flow of

input and instant response, enabling ongoing correction cycles to occur.



But these metrics are difficult to apply to an entire game’s interactivity all at once.

To answer the question of real-time control more easily, it’s useful to break down a

game’s interactions into individual mechanics. Then we can check each mechanic

against the various thresholds from our model.



Mechanics: Game Feel Atoms

For our purposes, a “game mechanic” is one complete loop of interaction, such as

a single mouse twitch, button press or foot stomp that can be traced through the

game’s programmed response and back to the player over and over again. Another

way to think about mechanics is as verbs. What are the player’s abilities in the

game? What can the player do? By this definition, examples of individual mechanics

include:





Pressing the A-button to jump in Super Mario Brothers







Steering Mario left and right using the D-Pad in Super Mario Brothers







Strumming a note in Guitar Hero







Using the mouse to steer left and right in flow







Boosting forward by clicking the mouse in flow







Drag-selecting a group of units in Starcraft







Clicking to send a group of selected units to a new location







Pressing a button at the right moment to advance to the next sequence in

Dragon’s Lair







Clicking on a button to select the next technology to research in Civilization 4



In a typical game, many different mechanics are active at the same time and often

overlap and combine. Running and jumping in Super Mario Brothers are separate



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