The Dynamic Layer - Game Design and Paper Prototyping - Introduction to Game Design, Prototyping, and Development (2015)

Introduction to Game Design, Prototyping, and Development (2015)

Part I: Game Design and Paper Prototyping

Chapter 5. The Dynamic Layer

Once players start actually playing a game, it moves from the inscribed layer into the dynamic layer of the Layered Tetrad. Play, strategy, and meaningful player choices all emerge in this layer.

This chapter explores the dynamic layer, various qualities of emergence, and how designers can anticipate the dynamic play that emerges from their inscribed design decisions.

The Role of the Player

A fellow designer once told me that a game isn’t a game unless someone is playing it. Although this might sound initially like a rehash of “if a tree falls in the woods, and there’s no one to hear it, does it make a sound?” it’s actually much more important for interactive media than any other medium. A film can still exist and show in a theater if there’s no one to watch it.1 Television can be sent out over the airwaves and still be television, even if no one is tuned to that station. Games, however, just don’t exist without players, for it is through the actions of players that games transform from a collection of inscribed elements into an experience (see Figure 5.1).

1 Some films, like the Rocky Horror Picture Show, owe a lot of their cult fandom to presentations in which the audience takes part, and the audience reactions in those films do alter the viewing experience of the other audience members. However, the film itself is completely unaffected by the audience. The dynamism in games comes from the ability of the medium to react to the player.


Figure 5.1 Players move the game from the inscribed layer into the dynamic layer

There are, of course, some edge cases to this, as there are to all things. The game Core War is a hacking game where players each try to write a computer virus that will propagate and take over a fake computer core from the viruses of their competitors. Players submit their viruses and wait for them to fight each other for memory and survival. In the yearly RoboCup tournament, various teams of robots compete against each other in soccer without any interference by the programmers during the game. In the classic card game War, players make no decision beyond the choice of which of the two decks to take at the beginning of the game, and the game plays out entirely based on the luck of the initial shuffle. Though in each of these cases, the player has no input and makes no choices during the actual play of the game, the play is still influenced by player decisions made before the official start of the match, and the players certainly have interest in and are waiting for the outcome of the game. In all of these cases, it still takes players to set up the game and to make the choices that determine its outcome.

Though players have a tremendous effect on the game and gameplay (including influences on the tetrad elements), players sit outside of the tetrad as the engine that makes it work. Players cause games to come into being and allow them to become the experience that has been encoded into the inscribed layer of the game by the game developers. As designers, we rely on players to aid us in helping the game to become what we intend. There are several aspects that are completely beyond our control as designers, including whether the player is actually trying to follow the rules, whether the player cares about winning or not, the physical environment in which the game is played, the emotional state of the players, etc. Because players are so important, we as developers need to treat them with respect and take care to ensure that the inscribed elements of the game, like rules, are clear enough to the players that they can decode them into the game experience that we intend.


The most important concept in this chapter is emergence, the core of which is that even very simple rules can beget complex dynamic behaviors. Consider the game of Bartok that you played and experimented with in Chapter 1, “Thinking Like a Designer.” Though Bartok had very few rules, complex play emerged from them. And, once you started changing rules and adding your own, you were able to see that even simple, seemingly innocuous rule changes had the potential to lead to large changes in both the feel and the play of the game.

The dynamic layer of the Layered Tetrad encompasses the results of the intersection of player and game across all four elements of the tetrad: mechanics, aesthetics, dramatics, and technology.

Unexpected Mechanical Emergence

My colleague Scott Rogers, author of two books on game design,2 once told me that he didn’t believe in emergence. After discussing it with him for a while, we came to the conclusion that he did believe in emergence, but he didn’t believe that it was legitimate for game designers to use emergence as an excuse for irresponsible design. Scott felt, and I believe, that as the designer of the systems within a game, you are responsible for the play that emerges from those systems. Of course, it’s extremely difficult to know what possibilities will emerge from the rules that you put in place, which is why playtesting is so critically important. As you develop your games, playtest early, playtest often, and take special care to note unusual things that happen in only one playtest. Once your game gets out in the wild, the sheer number of people playing will cause those unusual flukes to happen a lot more often than you would expect. Of course, this happens to all designers—look at some of the cards that have been declared illegal in Magic: The Gathering—but as Scott says, it’s important that designers own these issues and take care to resolve them.

2 Scott Rogers, Level up!: The Guide to Great Video Game Design (Chichester, UK: Wiley, 2010) and Scott Rogers, Swipe this! The Guide to Great Tablet Game Design (Hoboken, NJ: John Wiley & Sons, 2012).

Dynamic Mechanics

Dynamic mechanics are the dynamic layer of the elements that separate games and interactive media from other media; the elements that make them games. Dynamic mechanics include procedures, meaningful play, strategy, house rules, player intent, and outcome. As with the inscribed mechanics, many of these are an expansion of elements described in Tracy Fullerton’s book Game Design Workshop.3

3 Tracy Fullerton, Christopher Swain, and Steven Hoffman, Game Design Workshop: A Playcentric Approach to Creating Innovative Games (Burlington, MA: Morgan Kaufmann Publishers, 2008), chapters 3 and 5.


Mechanics in the inscribed layer included rules: instructions from the designer to the players about how to play the game. Procedures are the dynamic actions taken by the players in response to those rules. Another way to say this is that procedures emerge from rules. In the game Bartok, if you added the rule about a player needing to announce when they had only one card left, there was an explicit procedure presented in the rules that the active player needed to do so (once she had only one card left). However, there was also an implicit procedure in that rule: the procedure of other players watching the hand of the active player so that they could catch her if she forgot to announce it. Prior to this rule, there was no real reason for a player to pay attention to the game during another person’s turn, but this simple rule change altered the procedures of playing the game.

Meaningful Play

In Rules of Play, Katie Salen and Eric Zimmerman define meaningful play as play that is both discernable to the player and integrated into the larger game.4

4 Katie Salen and Eric Zimmerman, Rules of Play: Game Design Fundamentals (Cambridge, MA: MIT Press, 2003), 34.

Image Discernable: An action is discernable to the player if the player can tell that the action has been taken. For example, when you press the call button for an elevator, the action is discernable because the call button lights up. If you’ve ever tried to call an elevator when the light inside the button was burned out, you know how frustrating it can be to take an action and yet not be able to discern whether the game interpreted your action.

Image Integrated: An action is integrated if the player can tell that it is tied to the outcome of the game. For example, when you press the call button for the elevator, that action is integrated because you know that doing so will cause the elevator to stop on your floor. In Super Mario Bros., the decision of whether to stomp an individual enemy or just avoid it is generally not very meaningful because that individual action is not integrated into the overall outcome of the game. Super Mario Bros. never gives you a tally of the number of enemies defeated; it only requires that you finish each level before the time runs out and finish the game without running out of lives. In HAL Laboratories’ series of Kirby games, however, the player character Kirby gains special abilities by defeating enemies, so the decision of which enemy to defeat is directly integrated into the acquisition of abilities, and the decision is made more meaningful.

If a player’s actions in the game are not meaningful, she can quickly lose interest. Salen and Zimmerman’s concept of meaningful play reminds designers to constantly think about the mindset of the player and whether the interactions of their games are transparent or opaque from the player’s perspective.


When a game allows meaningful actions, players will usually create strategies to try to win the game. A strategy is a calculated set of actions to help the player achieve a goal. However, that goal can be anything of the player’s choosing and does not necessarily need to be the goal of winning the game. For instance, when playing with a young child or with someone of a lower skill level in a game, the player’s goal might be to make sure that the child enjoys playing the game and learns something, sometimes at the expense of the player winning the game.

Optimal Strategy

When a game is very simple and has few possible actions, it is possible for players to develop an optimal strategy for the game. If both players of a game are playing rationally with the goal of winning, an optimal strategy is the possible strategy with the highest likelihood of winning. Most games are too complex to really have an optimal strategy, but some games like Tic-Tac-Toe are simple enough to allow one. In fact, Tic-Tac-Toe is so simple that chickens have been trained to play it and force a draw or a win almost every time.5

5 Kia Gregory, “Chinatown Fair Is Back, Without Chickens Playing Tick-Tack-Toe,” New York Times, June 10, 2012.

An optimal strategy is more often a fuzzy idea of the kind of thing that would likely improve a player’s chance of winning. For instance, in the board game Up the River by Manfred Ludwig, players are trying to move three boats up a river to dock at the top of the game board, and arriving at the dock is worth 12 points to the first boat to arrive, then 11 points for the second boat, and down to only 1 point for the twelfth boat. Every round (that is, every time that all players have taken one turn), the river moves backward 1 space, and any boat that falls off the end of the river (the waterfall) is lost. Each turn, the player rolls 1d6 (a single six-sided die) and chooses which boat to move. Because the average roll of a six-sided die is 3.5, and the player must choose from among her three boats to move every turn, each boat will move an average of 3.5 spaces every three of her turns. However, the board will move backward 3 spaces every three turns, so each boat only makes an average forward progression of 0.5 spaces every three turns (or 0.1666, (or 1/6) spaces every turn).6

6 There are additional rules of the game that I’m omitting for the sake of simplicity in the explanation.

In this game, the optimal strategy is for the player to never move one of her boats and just let it fall off the waterfall. Then each boat would move forward an average of 3.5 spaces every two turns instead of three. With the board moving backward 2 spaces in two turns, this would give each of her boats an average movement forward of 1.5 spaces every two turns (or 0.75 spaces each turn), which is much better than the 0.1666 afforded to the player if she tries to keep all of her boats. Then this player would have a better chance of getting to the dock in first and second place, giving her 23 total points (12 + 11). In a two-player game, this strategy wouldn’t work because the second player would tie up at 10, 9, and 8 for 27 points, but in a three or four-player game, it’s the closest thing to an optimal strategy in this game. However, the other players’ choices, randomized outcomes of the dice, and other factors mean that it won’t always ensure a win; it will just make a win more likely.

Designing for Strategy

As a designer, you can do several things to make strategy more important in your game. For now, the main thing to keep in mind is that presenting the player with multiple possible ways to win will require her to make more difficult strategic decisions during play. In addition, if some of these goals conflict with each other while others are complementary (i.e., some of the requirements for the two goals are the same), this can actually cause individual players to move into certain roles as the game progresses. Once a player can see that she is starting to fulfill one of the goals, she will pick its complementary goals to pursue as well, and this will lead her to make tactical decisions that fulfill the role for which those goals were designed. If these goals cause her to take a specific type of action in the game, it can alter her in-game relationship with other players.

An example of this comes from the game Settlers of Catan, designed by Klaus Teuber. In this game, players acquire resources through random die rolls and trade, and some of the five game resources are useful in the early game while others are useful at the end. Three that are less useful at the beginning are sheep, wheat, and ore; however, together, the three can be traded for a development card. The most common development card is the soldier card, which can move the robber token onto any space, allowing the player moving it to steal from another player. Therefore, an excess of ore, wheat, and sheep at the beginning of the game can lead the player to purchase development cards, and because having the largest number of soldier cards played can earn the player victory points, the combination of that resource and that potential goal can influence the player to rob the other players more often and actually make her play the role of the bully in the game.

House Rules

House rules occur when the players themselves intentionally modify the rules. As you saw in the Bartok game example, even a simple rule change can have drastic effects on the game. For instance, most players of Monopoly have house rules that cut the auction of property (which happens if someone lands on an unowned property and chooses not to buy it) and add collection of all fines to the Free Parking space to be picked up by a player who lands on that space. The removal of the auction rule removes nearly all potential strategy from the beginning of Monopoly (converting it into an extremely slow random property distribution system), and the second rule removes some determinism from the game (since it could benefit any player, either the one in the lead or in last place). Not all house rules are bad, of course, and some make games considerably more fun.7 In all cases, however, they are an example of the players beginning to take some ownership of the game, making it a little more theirs and a little less the designer’s. The fantastic thing about house rules is that they are many people’s first experimentation with game design.

7 If you’re ever playing the game Lunch Money by Atlas Games, try allowing players to attack another player, heal themselves, and discard any cards they don’t want each turn (rather than having to choose one of the three). It makes the game a lot more frantic!

Player Intent: Bartle’s Types, Cheaters, Spoilsports

Something that you will have little or no control over is the intent of your players. While most players will be playing your game rationally to win, you may also have to contend with cheaters and spoilsports. Even within legitimate players of games, you will find four distinct personality types as defined by Richard Bartle, one of the designers of the first MUD (multi-user dungeon, a text-based online ancestor of modern massively multiplayer online roleplaying games). The four types of players that he defined have existed since his early MUD and carry through all multiplayer online games today. His 1996 article “Hearts, Clubs, Diamonds, Spades: Players Who Suit MUDs”8 contains fantastic information on how these types of players interact with each other and the game as well as information about how to grow your community of players in positive ways.

8 Richard Bartle, “Hearts, Clubs, Diamonds, Spades: Players Who Suit Muds,”, accessed February 2, 2014.

Bartle’s four types (which he also identified with the four suits of a deck of cards) are as follows:

Image Achiever (Diamond): Seeks to get the highest score in the game. Wants to dominate the game.

Image Explorer (Spade): Seeks to find all the hidden places in the game. Wants to understand the game.

Image Socializer (Heart): Wants to play the game with friends. Wants to understand the other players.

Image Killer (Club): Wants to provoke other players of the game. Wants to dominate the other players.

These can be understood as belonging to a 2x2 continuum (also from Bartle’s article). Figure 5.2 represents this graphically.


Figure 5.2 Richard Bartle’s four players who suit MUDs9

9 Adapted from: Richard Bartle, “Hearts, Clubs, Diamonds, Spades: Players Who Suit Muds,”, accessed February 2, 2014.

There are certainly other theories of player motivation and player types,10 but Bartle’s are the most widely recognized and understood in the game industry.

10 See Nick Yee’s “Motivations of Play in MMORPGs: Results from a Factor Analytic Approach,”

The other two player types that you may encounter are cheaters and spoilsports:

Image Cheaters: Care about winning but don’t care about the integrity of the game. Cheaters will bend or break the rules to win.

Image Spoilsports: Don’t care about winning or about the game. Spoilsports will often break the game to ruin other players’ experiences.

Neither of these are players that you want in your game, but you need to understand their motivations. For instance, if a cheater feels that she has a chance of winning legitimately, she may not feel as driven to cheat. Spoilsports are much more difficult to deal with since they don’t care about the game or winning, but you rarely have to deal with spoilsports in digital single-player games, because they would have no reason to play the game if they weren’t interested in it in the first place. However, even great players can sometimes become spoilsports when they encounter terrible game mechanics...often right before they choose to turn the game off.


Outcome is the result of playing the game. All games have an outcome. Many traditional games are zero sum, meaning that one player wins and the other loses. However, this is not the only kind of outcome that a game can have. In fact, every individual moment in a game has its own outcome. There are several different levels of outcome in most games:

Image Immediate outcome: Each individual action has an outcome. When a player attacks an enemy, the outcome of that attack is either a miss or a hit and the resultant damage to the enemy. When a player purchases property in Monopoly, the outcome is that the player has less money available but now owns the potential to earn more money.

Image Quest outcome: In many games, the player will be sent on missions or quests and will gain some sort of reward for completing that quest. Missions and quests often have narratives constructed around them (e.g., a little girl has lost her balloon in Spider-man 2, so Spider-man must retrieve it for her), so the outcome of the quest also marks the end of the tiny narrative surrounding it.

Image Cumulative outcome: When the player has been working toward a goal over time and finally achieves it, that is a cumulative outcome. One of the most common examples of this is leveling up in a game with experience points (XP). Everything that the player does accrues a few experience points, and once the total number of XP has reached a threshold, the player’s in-game character gains a new level, which grants the character a boost in stats or abilities. The main difference between this and a quest outcome is that the cumulative outcome usually doesn’t have a narrative wrapped around it, and the player often reaches the cumulative outcome passively while actively doing something else (e.g., a player of Dungeons & Dragons 4th Edition actively takes part in a game session and then, while adding up earned XP at the end of the evening, notices that she has reached 10,000 XP and achieved level 7).11

11 Rob Heinsoo, Andy Collins, and James Wyatt, Dungeons & Dragons Player’s Handbook: Arcane, Divine, and Martial Heroes: Roleplaying Game Core Rules (Renton, WA: Wizards of the Coast, 2008).

Image Final outcome: Most games have an outcome that ends the game: A player wins chess (and the other loses), a player finishes Final Fantasy VII and saves the world from Sephiroth, and so on. There are a few games where the final outcome doesn’t end the game (e.g., in Skyrim, even when the player has finished the main quest, she can still continue to play in the world and experience other quests). Interestingly, the death of the player character is very rarely a final outcome in games.

In the few games where death is a final outcome (e.g., the game Rogue, where a single loss will cause the player to lose all progress in the game), the individual game session is usually relatively short so that the player doesn’t feel a tremendous loss at the death of the player character. In most games, however, death is just a temporary setback and in-game checkpoints usually ensure that the player never loses more than five minutes of progress in the game.

Dynamic Aesthetics

Just as with dynamic mechanics, dynamic aesthetics are those that emerge when playing the game. There are two different primary categories:

Image Procedural aesthetics: Aesthetics that are programmatically generated by digital game code (or via the application of mechanics in a paper game). These include procedural music and art that emerge directly from inscribed aesthetics and technology.

Image Environmental aesthetics: These are the aesthetics of the environment in which the game is played, and they are largely beyond the control of the game developers.

Procedural Aesthetics

Procedural aesthetics, as we generally think of them, are created programmatically by combining technology and inscribed aesthetics. These are called procedural because they arise from procedures (also known as functions) that have been written programming code. If you look at the cascading waterfall of objects that is created in the first programming chapter (Chapter 18, “Hello World: Your First Program”), that could be considered procedural art because it is an interesting visual that emerges from C# programming code. In professional games, two of the most common forms of procedural aesthetics are music and visual art.

Procedural Music

Procedural music has become very common in modern videogames, and it is currently created through three different techniques:

Image Horizontal Re-Sequencing (HRS): HRS rearranges the order of several precomposed sections of music according to the emotional impact that the designers wish for the current moment in the game. An example of this is LucasArts’ iMUSE (Interactive MUsic Streaming Engine), which was used in the X-Wing game series as well as many of LucasArts adventure games. In X-Wing, the pre-composed music is sections of John William’s score for the Star Wars films. Using iMUSE, designers are able to play peaceful music when the player is just flying through space, ominous music when enemy forces are about to attack, victory music whenever a player destroys an enemy craft or achieves an objective, and so on. There are also longer sections of music that are meant to loop and provide a single mood as well as very short sections of music (one or two measures in length) that are used to mask the transition from one mood to the next. This is currently the most common type of procedural music technology and harkens at least as far back as Super Mario Bros., which played a transitional musical string and then switched background music when the player had less than 99 seconds to complete the current level.

Image Vertical Re-Orchestration (VRO): VRO includes recordings of various tracks of a single song that can be individually enabled or disabled. This is used very commonly in rhythm games like PaRappa the Rapper and Frequency. In PaRappa, there are four different tracks of music representing four different levels of success for the player. The player’s success is ranked every few measures, and if she either drops or increases in rank, the background music switches to a worse- or better-sounding track to reflect this. In Frequency and its sequel Amplitude, the player controls a craft traveling down a tunnel, the walls of which represent various tracks in a studio recording of a song. When the player succeeds at the rhythm game on a certain wall, that track of the recording is enabled. Amplitude includes a mode where players can choose which tracks to enable at any point in the song to create their own remix of the tracks included with the game. This is nearly ubiquitous in rhythm games—with the fantastic Japanese rhythm game Osu Tatake Ouendan! and its Western successor Elite Beat Agents as marked exceptions—and has also become common in other games to give the player musical feedback on the health of their character, speed of their vehicle, and so on.

Image Procedural Composition (PCO): PCO is the most rare form of procedural music because it takes the most time and skill to execute. In PCO, rather than rearrange various precomposed tracks of music or enable and disable precomposed tracks, the computer program actually composes music from individual notes based on programmed rules of composition, pacing, etc. One of the earliest commercial experiments in this realm was C.P.U. Bach by Sid Meier and Jeff Brigs, a title for the 3DO console. In C.P.U. Bach, the player was able to select various instruments and parameters, and the game would craft a Bach-like musical composition based on procedural rules.

Another fantastic example of procedural composition is the music created by composer and game designer Vincent Diamante for the game Flower by thatgamecompany. For the game, Diamante created both precomposed sections of music and rules for procedural composition. During gameplay, background music is usually playing (some of which is re-arranged based on the situation using HRS) as the player flies over flowers in a field and opens them by passing near. Each flower that is opened creates a single note as it blooms, and Diamante’s PCO engine chooses a note for that flower that will blend harmoniously with the precomposed music and create a melody along with other flower notes. Regardless of when the player passes over a flower, the system will choose a note that fits well with the current audio soundscape, and passing over several flowers in sequence will procedurally generate pleasing melodies.

Procedural Visual Art

Procedural visual art is created when programming code acts dynamically to create in-game visuals. There are a few forms of procedural visuals with which you are probably already familiar:

Image Particle systems: As the most common form of procedural visuals, particle systems are seen in almost every game these days. The dust cloud that rises when Mario lands a jump in Super Mario Galaxy, the fire effects in Uncharted 3, and the sparks that appear when cars crash into each other in Burnout are all various versions of particle effects. Unity has a very fast and robust particle effects engine (see Figure 5.3) that you will use to create a fire spell in Chapter 35, “Prototype 8: Omega Mage.”


Figure 5.3 Various particle effects that are included with Unity

Image Procedural animation: Procedural animation covers everything from flocking behavior for groups of creatures to the brilliant procedural animation engine in Will Wright’s Spore that created walk, run, attack, and other animations for any creature that a player could design. With traditional animation, the animated creatures always follow the exact paths inscribed by the animator. In procedural animation, the animated creatures follow procedural rules that emerge into complex motion and behavior. You will get some experience with the flocking behavior known as boids in Chapter 26, “Object-Oriented Thinking” (see Figure 5.4).


Figure 5.4 Boids, an example of procedural animation from Chapter 26

Image Procedural environments: The most obvious example of a procedural environment in games is the world of Minecraft by Mojang. Each time a player starts a new game of Minecraft, an entire world (billions of square kilometers in size) is created for her to explore from a single seed number (known as the random seed). Because digital random number generators are never actually random, this means that anyone who starts from the same seed will get the same world.

Environmental Aesthetics

The other major kind of dynamic aesthetics are those controlled by the environment in which the game is played. While these are beyond the control of the game designer, it is still the designer’s responsibility to understand what environmental aesthetics might arise and accommodate them as much as possible.

Visual Play Environment

Players will play games in a variety of settings and on a variety of equipment, so it’s necessary as a designer to be aware of the issues that this may cause. You should accommodate two elements in particular:

Image Brightness of the environment: Most game developers tend to work in environments where the light level is carefully controlled to make the images on their screen as clear as possible. Players don’t always interact with games in environments with perfect lighting. If your player is on a computer outside, playing on a projector, or playing anywhere else with imperfect control of lighting, it can be very difficult for them to clearly see scenes in your game that are meant to be taking place in a dark setting. Remember to make sure that your visual aesthetic either has a lot of contrast in it between light and dark or allows the player the ability to adjust the gamma or brightness level of the visuals. This is especially important if designing for a phone or other mobile device, since these can easily be played outside in direct sunlight.

Image Resolution of the player’s screen: If you are developing for a fixed-screen device like the iPad or PSVita, this won’t be an issue. However, if you’re designing for a computer or game console, you have very little control over the resolution or quality of your player’s screen, particularly if it’s a console game. You cannot assume that your player will have a 1080p or even 720p screen. All modern consoles before the PS4 and Xbox One could still output the standard composite video signal that has existed for standard-definition television since the ’50s. If you’re dealing with a player on a standard-def television, you will need to use a much larger font size to make it at all legible. Even AAA games like Mass Effect, The Last of Us, and Assassin’s Creed don’t accommodate this well, and it is impossible to read critical text in these games on any television made more than 10 years ago. You never know when someone might be trying to play your game on older equipment, but you can detect whether this is the case and change the font size to help them out.

Auditory Play Environment

As with the visual play environment, you rarely have control over the audio environment in which your game is played. Though this is essential to understand when making a mobile game, it’s also important to keep in mind for any game. Things to consider include the following:

Image Noisy environments: Any number of things may be happening at the same time as your game, so you need to make sure that your player can still play even if they miss or can’t hear some of the audio. You also need to make sure that the game itself doesn’t create an environment so noisy that the player misses critical information. In general, important dialog and spoken instructions should be the loudest sounds in your game, and the rest of the mix should be kept a little quieter. You will also want to avoid subtle, quiet audio cues for anything important in the game.

Image The player controls the volume: The player might mute your game. This is especially true with mobile games where you can never count on the player to be listening. For any game, make sure that you have alternatives to sound. If you have important dialogue, make sure to allow the player to turn on subtitles. If you have sound cues to inform players of where things are, make sure to also include visual cues as well.

Player Considerations

Another critical thing to consider about the environment in which your game will be played is the player herself. Not all players have the optimal ability to sense all five aesthetics. A player who is deaf should really be able to play your game with little trouble, especially if you follow the advice in the last few paragraphs. However, there are two other considerations in particular that many designers miss:

Image Colorblindness: About 7% to 10% of Caucasian men have some form of colorblindness. There are several different forms of deficiency in color perception, the most common of which causes a person to be unable to differentiate between similar shades of red and green. Because colorblindness is so common, you should be able to find a colorblind friend that you can ask to playtest your game and make sure that there isn’t key information being transmitted by color in a way that they can’t see. Another fantastic way to check for your game is to take a screen shot and bring it into Photoshop. Under the View menu in Photoshop is a submenu called Proof Setup, and in there, you can find settings for the two most common types of color blindness. This will enable you to view your screen shot as it would be viewed by your colorblind players.

Image Epilepsy and migraine: Both migraines and epileptic seizures can be caused by rapidly flashing lights, and children with epilepsy are particularly prone to having seizures triggered by light. In 1997, an episode of the Pokemon television show in Japan triggered simultaneous seizures in hundreds of viewers because of flickering images in one scene.12 Nearly all games now ship with a warning that they may cause epileptic seizures, but the occurrence of that is now very rare because developers have accepted the responsibility to consider the effect their games might have on their players and have removed rapidly flashing lights from their games.

12 Sheryl WuDunn, “TV Cartoon’s Flashes Send 700 Japanese Into Seizures,” New York Times, December 18, 1997.

Dynamic Narrative

There are several ways of looking at narrative from a dynamic perspective. The epitome of the form is the experience of players and their game master when playing a traditional pen-and-paper roleplaying game. While there have certainly been experiments into crafting truly interactive digital narratives, after over 30 years, they still haven’t reached the level of interaction in a well-run game of Dungeons & Dragons (D&D). The reason that D&D can create such fantastic dynamic narratives is that the dungeon master (DM: the player running the game for the others) is constantly considering the desires, fears, and evolving skills of her players and crafting a story around them. As mentioned earlier in this book, if the players run into a low-level enemy that (due to random die rolls working in its favor) is very difficult to fight, the DM can choose to have that enemy escape at the last minute and then return as a nemesis for the players to fight later. A human DM can adapt the game and the game narrative to the players in a way that is very difficult for a computer to replicate.

Interactive Narrative Incunabula

In 1997, Janet Murray, a professor at the Georgia Institute of Technology, published the book Hamlet on the Holodeck13 in which she examined the early history of interactive narrative in relation to the early history of other forms of narrative media. In her book, Murray explores the incunabular stage of other media, which is the stage when that medium was between its initial creation and its mature form. For instance, in the incunabular stage of film, directors were attempting to shoot 10-minute versions of Hamlet and King Lear (due to the 10-minute length of a single reel of 16mm film), and incunabular television was largely just televised versions of popular radio programs. Having many examples from other media, Murray proceeds to talk about the growth of interactive digital fiction and where it is currently in its incunabular stage. She covers early Infocom text adventure games like the Zork series and Planetfall and points out two very compelling aspects that make interactive fiction unique.

13 Janet Horowitz Murray, Hamlet on the Holodeck (New York: Free Press, 1997).

Interactive Fiction Happens to the Player

Unlike nearly every other form of narrative, interactive fiction is happening directly to the player. The following happens near the beginning of the game Zork. (The lines preceded by a right angle bracket [e.g., > open trap door] are the commands entered by the player.)

...With the rug moved, the dusty cover of a closed trap door appears.

> open trap door

The door reluctantly opens to reveal a rickety staircase descending
into darkness.

> down

It is pitch dark. You are likely to be eaten by a grue.

> light lamp

The lamp is now on.
You are in a dark and damp cellar with a narrow passageway leading
east and a crawlway to the south. To the west is the bottom of a
steep metal ramp which is unclimbable.
The door crashes shut, and you hear someone barring it.14

14 Zork was created at the Massachusetts Institute of Technology in 1977-79 by Tim Anderson, Marc Blank, Bruce Daniels, and Dave Lebling. They formed Infocom in 1979 and released Zork as a commercial product.

The key element here is that you hear someone barring it. You are now trapped. Interactive fiction is the only narrative medium where the player/reader is the character taking actions and suffering consequences in the narrative.

Relationships Are Developed Through Shared Experience

Another compelling aspect of interactive fiction is that it allows the player to develop a relationship with other characters through shared experience. Murray cites Planetfall,15 another Infocom text adventure, as a fantastic example of this. Following the destruction of the spaceship on which she was a janitor, the player is largely alone for the first section of Planetfall. Eventually, she comes across a machine to make warrior robots, but when she engages it, it malfunctions and produces a child-like, mostly useless robot named Floyd. Floyd follows the player around for the remainder of the game and does little more than provide comic relief. Much later in the game, there is a device locked in a bio-lab that the player must retrieve, but the lab is full of both radiation and vicious aliens. Immediately, Floyd simply says “Floyd go get!” and enters the lab to retrieve the item. Floyd soon returns, but he is leaking oil and barely able to move. He dies in the player’s arms as she sings the Ballad of the Starcrossed Miner to him. Many players reported to the designer of Planetfall, Steven Meretzky, that they cried when Floyd died, and Murray cites this as one of the first examples of a tangible emotional connection between a player and an in-game character.

15 Planetfall was designed by Steve Meretzky and published by Infocom in 1983.

Emergent Narrative

True dynamic narrative emerges when the players and game mechanics contribute to the story. Several years ago, I was playing in a Dungeons & Dragons 3.5 edition game with some friends. The game master had us in a pretty tight spot. We had just retrieved an artifact from some forces of evil in another dimension and were being chased by a large balrog16 as we fled down a narrow cave on our flying carpet toward the portal back to our dimension. It was gaining on us quickly, and our weapons were having little effect. However, I remembered a little-used property of the Rod of Splendor that I possessed. Once per week, I could use the Rod of Splendor to create a huge pavilion of silk, 60 feet across, inside of which were the furnishings and food for a party to entertain 100 people.17 Usually, we would use this capability of the rod to throw a party when we’d finished a mission, but this time I cast the tent directly behind us in the tunnel. Because the tunnel was only 30 feet wide, the balrog crashed into the tent and became entangled, allowing us to escape without anyone dying.

16 A balrog is the giant winged demon of fire and smoke that faced Gandalf in the “you shall not pass” scene of The Fellowship of the Ring by J. R. R. Tolkien.

17 The Dungeons & Dragons 3.5e System Reference Document entry for the Rod of Splendor is at

This kind of unexpected story emerges from a combination of the situation created by the game master, the game’s rules, and the creativity of individual players. I have encountered many similar stories through the roleplaying campaigns that I have been part of (as both a player and game master), and you can do several things to encourage this kind of collaborative storytelling in roleplaying campaigns that you run. For more information about roleplaying games and how to run a good campaign, see the “Roleplaying Games” section of Appendix B, “Useful Concepts.”

Dynamic Technology

As with the previous chapter, because other large sections of this book are devoted to game technology it is covered very little in this chapter. The core concept for you to know at this point is that the game code you author (your inscribed technology) will be a system that runs as the player is experiencing the game. As with all dynamic systems, emergence will occur, and this means that there is both the opportunity for wonderful, unexpected things to happen and the danger of horrible, unexpected things to happen. Dynamic technology covers all of the runtime behavior of your code and the ways in which it affects the player. This could be anything from a system to simulate physics to artificial intelligence code to anything else that is implemented in your code.

To find information on the dynamic behavior of paper game technologies such as dice, spinners, cards, and other randomizers, look to Chapter 11, “Math and Game Balance.” For information on digital game technologies, you can look to the latter two parts of the book as well as Appendix B.


Dynamic mechanics, aesthetics, narrative, and technology all emerge from the act of players playing a game. While the elements that emerge can be challenging to predict, it is the responsibility of designers to playtest in order to understand the envelope of that emergence.

The next chapter will explore the cultural layer of the Layered Tetrad, the layer beyond gameplay. It is in the cultural layer that players gain more control over the game than the original game developers, and it is the cultural layer that is experienced by members of society who do not ever play the game themselves.