The Hows and Whys of Level Design

With no professional experience I can't really dive into many aspects of level design or game design. Nonetheless, there are some comments I'd like to share. I may be stretching too far but I think that some aspects of level design cross paths with some aspects of psychology. This is no way intended to be a scientific article.

Design

The creation of a new world

Hourences put emphasis on how important it is to have a good beginning and a clear one. One of his ideas is a checklist and a flow chart. In here I'd comment that sometimes people can become stuck in that stage for too long. I can't diagnose anybody but if at that stage the person or boss is over-preoccupied with schedules and charts of any kind, it may be a symptom of some type of fear or excessive perfectionism. If the person is stubborn, kind of unrelenting in his views and does not accept changes or criticism, it may be a personality disorder. On the other side, if the plan is always changed over and over and there is never a clear direction, it could be some form of executive function impairment.

One of the things related to executive functioning is decision making and if the person cannot decide and keeps having second thoughts, we have a problem. Hourences said that the planning stage should be crucial in making it clear where to go and where to begin at. I agree with that, but I can also see that sometimes that "exactness" is a problem because there is never a perfect plan to begin with. What we cannot do is to give excuses to not plan ahead of time, in which case I'm agreeing with Hourences again. He called "Restart Syndrome", when the design is literally restarted over and over. This could be a symptom of Obsessive Compulse Personality Disorder. I really can't tell when it's the case of OCPD and when it's not though. The best I can do is to be suspicious that if the person is obsessed with doing it right, seeking for a degree of perfection and never quite reaching it, it can't be healthy and normal. Another issue that may be present is more related to memory and the person not remembering when they started something or if they did even start it, which could result in the same "restart syndrome" as he called it.

Failure to focus on one design. Failure to focus on multiple aspects of one design. Failure to predict how complex or how long a task is going to take. The opposite, hyperfocus and/or obsession with a single thing. All that is related to executive functioning too. If the person feels defeated too often and/or too soon. By too soon I mean somewhere around a third or less of the project being completed. It means that we have a problem with underestimating the project's complexity and/or overestimating our own skills. It can also be that the person is unable to maintain their motivation and/or energy for long enough to finish the project, which can be the symptom of some mental health issue going on. The opposite problem, never quitting or never knowing when to stop, it's a sign of some unhealthy mindset. We have to know that some projects can't and won't last forever.

"Can I do this?". This question is part of Hourence's checklist. From my personal experience, if we fail to deliver it, it must be due to the lack of experience. As we grow older and gain more experience, we tend to make better judgements about time, feasibility and are better able to foresee problems. But that isn't always the case and then we have to discuss cognitive bias. There are lots of research in this area and biased opinions are just about everywhere we go. If the answer to the previous question is always detached from reality and devoid of a deeper insight, then we could have a case of trauma, a personality disorder or something that is hindering the ability to think straight. In one extreme we have people who always answer yes even when they are clearly not capable of doing it. In the other extreme we have people who always answer no, regardless of their strengths or good qualities that they may possess. If the answer is always "not sure" this is probably a sign of some form of insecurity, whichever it may be.

I'll give a personal example. I once was so amazed by Max Payne that I thought I could recreate the levels of it inside one giant level for Unreal Tournament Single Player mod. I thought that it'd be an easy task because the Max Payne levels were already done. All I had to do was to copy them. After many years dragging that project on it became a burden. Until I admitted defeat and quit. The crux of the issue was misjudgment and biased view on how time consuming and hard, how much skills you are required, to start and finish such a gargantuan project. I was really trying to make the largest single player level ever for the game, pushing the engine to its limits without realizing that it could have never been done. From a psychological and developmental view, every person is ought to have this experience in one way or another in their lives.

Floorplan. There is one key aspect of all companies that is inter communication between people and different departments. In here Hourences argues that the best floorplan comes from a combination of both aesthetics and gameplay, in which case I agree. So much trouble can be avoided if we are able to foresee problems before they even arise. Conversely, so much problems arise because, for one or more reasons, gameplay and aesthetics didn't talk to each other during this stage. Hourences argues that drawing is the best form of communication to convey your ideas of level design. In here I disagree. Imagine that you draw or take a picture of a lonely mountain on a landscape. Unless there is only one way to interpret that picture, sometimes you have to use words to explain something. Pictures to convey atmosphere, style and gameplay are great indeed in conveying your ideas. But it may happen that the other person sees something different or have a different perspective and this could result in miscommunication.

Success and Efficiency. In here I'd like to comment that when somebody is literally obsessed with success and/or efficiency, that's probably some mental health issue going on. I cannot make any diagnoses here, but when success and/or efficiency become the sole driving force and we have lost the purpose, we have a problem. Efficiency is a pathway to success, not the other way around, success preceding efficiency. To give a practical example of obsession with efficiency: suppose that you have 1 GB of memory to be filled with a level and all its assets. We do not have any obligation to fill exactly 1 GB of memory. Nor any obligation to leave some memory unused. Any bytes left unused are not going to cause any harm to the game. Time is a different story though. If the game takes advantage of pre processing something and this pre processing stage takes 1 hour less due to optimizations, it's a good thing. However, being obsessed by saving 1 minute of pre processing time per day is probably a waste of effort because if the level takes 3 months to be made, saving 1 or 3 days from 3 months is not something that should be seen as critical. On the opposite side, to save 1 day from something that is multiplied by 100, then we aren't talking about saving just 1 day, but 100 days which is a lot of time. Sometimes we have hidden "black holes" in our workflows, but the obsession with finding them can be equally harmful. I don't have clear answers and magical recipes to solve everything.

Originality. I have to add my personal experience here. There is map for Unreal called Radikus. It features portals that you can see through and give the illusion of another dimension at the other side. I was so obsessed with that idea at one point that I wished to make a map that would have two worlds in one map. The vague idea that I had was more or less the same that you see in movies that deal with multiple universes or any parallel dimension that exists in the same space as the real world. For a long time I tried, but it failed miserably. For starters the idea was never clear. I never had a clear view of how I'd accomplish it. Much less on how it'd look like.

Originality equates to anything that is unusual and/or unique. Anything relating to the world of super heroes, fantasy realms or even a psychedelic experiences. Sometimes artists are (wrongly) portrayed as drug addicts or mentally abnormal people, which just adds to prejudice I must say. We all want to be original, don't we? If a person is completely devoid of any desire to be original, that can also be a problem and a sign of some metal health issue too. What we must be aware of is that obsession with being original hurts and this can explode in losing relationships, losing jobs or losing ourselves in extreme cases. The lesson that Hourences is trying to give is that originality means nothing if being original is the same as unfeasible, unfaithful, unreasonable or impractical. This again links to executive functions of the brain because when a person ruptures from reality, we have a serious mental health issue going on. There are numerous research studies about creativity and mental health disorders but that's not the point I'm making here.

I should add that being original is also a matter of ego. Everyone has its own identity and this, in terms of level design and game design, is expressed by means of striving for originality. We should be careful with our own egos because if it grows insatiable we risk ourselves into losing people, losing workplaces, losing everything that matters to us and, in extreme cases, losing life itself. It can be quite dangerous. That's why I condemn that idea of great artists who were great because they suffered from some serious mental illness. Artists going "crazy" isn't the right way to explain their art. Because an artist must retain some cognitive functions intact to be able to produce their art, else they can't work.

As a side note I'd like to comment that if there is a person who is putting his or her ego above everything else, demanding everyone around to comply to his or her views in detriment of even discussing them in the first place. Or, if it's the case of somebody who is refusing to comply all together, refusing to accept any opinion other than his or her own. That's some serious sign of a personality disorder, trauma or some other mental health issue and game design or level design would just be another place for this to happen. I'm not talking about people who are having a mental breakdown or a psychotic crisis, but people who are very much aware of reality and the people around but have a personality or behaviors that are very antagonistic and/or challenging in multiple ways. Two words here would be "delusion" and "grandiosity", which describe narcissistic personality. Now be careful here because delusion and grandiosity may be related to something else other than narcissism.

Clichés. In a straightforward definition, cliches are the patterns that people instantly recognize as familiar patterns. For example: jump scary moments when a loud sound or music is played, with anything from a corpse falling from above to a bird flying in front of you. If we are obsessed with originality we may very well fall in the trap of not using cliches because we want to be original, right? A red cross is an universal sign of health; two serpents with a winged-staff is the universal sign of medical care; traffic lights use red to signal stop and green to signal free to pass; snow covering the streets means winter; sand and scorching sun means hot and dry. If we avoid the obvious clichés at all costs we risk making things that convey no meaning at all or are not recognizable by the players at all. Being original isn't always about doing something new, but also in doing something creative with existing ideas or concepts.

Let's say that a level has to be dry and a desert. The most obvious cliché is to build a level that takes place in a desert with sand. But that's only one interpretation of a desert. There is also the icy desert, which is also a land mostly devoid of life forms. Depending on what the game is about we have other types of deserts, some metaphorical, such as ghost towns. How many environments could you relate to the word "emptiness" if you were to think right now? Quite a few. We are sort of blurring the lines between originality and clichés here, because a desert is a desert but how we approach it depends on what we want to achieve. In one extreme there is the danger of losing originality by being too fearful to be bold and also the fear of doing a boring level or game. In the other end there is the danger of striving so hard to be original that the intentions, original purposes (ironically), are lost.

Concept art. In simple terms those are concepts that depict how a scene is going to be like in a movie or how an environment is supposed to be in level design. Hourences says here that concept artists are not level designers because they are more aligned with how it looks and how it feels, not in how it plays. Are there people who excel in both? Certainly yes and probably rare to find. I myself never made any concept art so I can be sure that I don't have the knowledge to criticize concept artists. The point that Hourences is trying to make is that concept arts are not floorplans or blueprints. They are made to convey a concept, as the name implies. As Hourences himself says in the book, there must be a tight alignment between concept and execution because problems in one can be caused by or be a consequence of problems in the other. Without experience I really can't tell how to tackle this.

Gameplay

Core gameplay x Map gameplay. The distinction that Hourences make is pretty clear. Core is about the game's rules and to what extend the player can interact with the game's world. Map is about placing challenges that are specific to that map and the player has to use the powers and abilities that the game provides to pass a level or a certain area. Both are intertwined and for the good they can't be split from each other.

Let's say you have a superhero with the power to fly. If the level is all indoors with no opportunity to fly at all we have a mistake. The exception is when we have strong storyline reasons to do that. And we also have the opposite. If the player can fly over all obstacles and skip them, the map's gameplay is not correctly intertwined with the core's gameplay. To give a very simple and crude example: there are games with modding tools such as Unreal Tournament. Some servers run mods that multiply health by 10, add automatic regeneration and infinite ammo. The player's experience is mostly ruined because the player lose the challenge with infinite health and ammo. I have played a mod called Monster Hunt and most servers run that infinite ammo and health mods that make all maps lose their challenge because the server is changing the core aspects of the game. How does some level designers compensate for that? Some of the maps designed for Monster Hunt and with infinite ammo and health in mind employ bosses with extra high health, traps that deal a lot of damage and obstacles that are just plain impossible to pass if the server is not running the infinite ammo and health mod. See how the core gameplay ends up being tied to the map gameplay?

Any game with puzzle solving emphasis is a great example of a combination of map gameplay and core gameplay. In the 2D sidescrolling world we have examples ranging from Prince of Persia, Super Mario, Sonic to Trine and Shoot em Up (shumps for short). Think about Super Mario. In all levels there are bricks which the player can break. Some specific levels have map specific mechanics such as flying or swimming. Think about Shoot em Up such as R-Type series with its multiple weapons. One weapon fires laser beams that ricochet from walls and some levels are designed with walls for that weapon. Sonic is another great example because some specific levels present map specific gameplay, such as flying with air currents or using an air bubble shield in underwater levels.

In the 3D world great examples come from Bioshock, Jedi Knight, Tomb Raider and other games. Lara Croft can grab on ledges, swim, jump high, escalate walls, swing on ropes, crawl and some other abilities. The levels in the Tomb Raider series focus on one or more of those Lara's abilities to present challenges for the player to solve. The Jedi Knight games do the same thing. Each level presents challenges that the player has to pass by taking advantage of the Jedi powers. There are even twists that happen in unexpected ways. Unreal Tournament and Urban Terror have servers dedicated to the art of jumping. There are those racing tracks where the player has to use their jumping and hopping skills to traverse various obstacles. Some of those obstacles even defy the laws of physics and that's due to game's simplified physics model, which sacrifices realism and priorizes the gameplay.

Mark Rosewater talks about designing for Magic the Gathering and he says that designers often have a big ego and attempt to please themselves. That's a mistake! Your audience is to be pleased by you, not yourself. The mechanics and gameplay are meant to be played and experienced by your audience. There is an important aspect that he talks about that is how the player feels the game and bad mechanics lead to bad gameplay. In MTG there are quite a few mechanics that were dropped over time because they were harming the game. In level design and game design the same mistake can happen.

Over the years MTG has shifted its focus from some types of cards towards others. For example: they decided that players should be able to interact with each other and this means that cards with effects that completely block out all spells should not be common. They want players to have answers to threats and the answers themselves have the risk of becoming even bigger threats. That's a very hard balance to achieve and MTG constantly faces player's dissatisfaction over that issue. About gameplay I'd argue that we very much face the same issue. Players want to interact with game world but at the same time, some types of interaction may be undesirable or even become boring over time. One quick example is elevators or lifts. If the speed is too high or too low it may impose problems for the player for which he or she cannot solve because they were programmed that way.

Abstract floorplan x Realistic floorplan. The way Hourences distinguishes the two is pretty much the same idea that Mark Rosewater has when talking about Top down vs Bottom up design. Are you going to priorize mechanics and gameplay first or aesthetics and theme first? I'd argue that there isn't a perfect balance between the two and more often than not games adopt both strategies in their levels. As the name implies, realistic is about real world settings. Think about hospitals, cities, subways, office buildings and so on. Abstract is more about alien worlds, fantasy realms or anything that wouldn't be built in the real world.

The point that I'd make here is that the easiest concepts to grasp is by either going full abstract or full realism. For example a subway system for Counter Strike. The setting is pretty clear in terms of atmosphere and feels. Now if you think on Lord of the Rings movies, a fantasy realm floorplan has more freedom in terms of concessions as realism is not necessarily the main goal. The more difficult place to be is when floorplans are hybrid, somewhere in between abstract and realistic. This is the case of games such as F.E.A.R. 2, which blends realistic environments with horror themes.

Realistic doesn't necessarily means feasible or an exact copy of a real world setting. By that I mean that there are concessions made due to gameplay. For example: in a real world bathroom there is only one door to enter or exit. In a game world, however, we can have two doors and even some third entrance with a ventilation system for example. It depends on the gameplay. Conversely, abstract doesn't mean that we are free to do whatever we want. We can have floating islands or castles if we want to. But there should be a good excuse for that. Either story-wise or gameplay-wise. The point that I'm making is that even in an abstract world we are unconsciously comparing it against common sense and the real world, meaning that if there is something off, the players are going to notice it. For example: if the level is the inside of a spaceship, it has to convey the interior of a spaceship as obvious as it may sound.

If I were to compare to architects and engineers of real world structures I'd say that there are some similarities with level design. For example: when engineers project a subway system there are concerns about capacity and space, which are more or less the same within a game world. However, a key difference is that the game world is tied to its gameplay and trying to build an exact copy of a real world subway system with real world measures won't work. Vending machines inside subway stations are always located near the stairs, entrances or exits, never far away at the platform's end. In game setting that's not always the case if there is a reason to place a vending machine at the platform's end for example.

I personally think that building game worlds is similar to an architects or engineers job. In a real world hospital the floorplan has to account for emergency exits, the flow of people, contamination risks, safeguarding measures against fire, etc. In a game world we have to account for who is going to play there and what gameplay is to be expected. I completely agreed with Hourences here in saying that the better your plan is to begin with, the better you are foreseeing possible problems ahead of time.

Terrain

Most modern engines can create terrain from heightmaps. A heightmap is a grayscale texture where black represents down and white represents up. It's quick and easy to have a mountain and valleys with it. However, a heightmap can only control the Z axis. It cannot handle more than two dimensions, meaning that we can't have tunnels and bridges unless we do it with 3D models. Hourencens is against the usage of heightmaps for cliffs, sharp edges and the attempt to add variation to the terrain by means of random noise filters. It just doesn't look natural at all.

Terrain texturing. The same discussion about contrast is made here by Hourences. The multiple terrain's textures have to be cohesive and have a good combination of colors and style. For example: to have mountains with brown terrain with random patches of green grass won't look good, both because of the color contrast and the random placement of the grass. One technique he gives is to use an intermediate texture to make the transition between two different textures smoother. For example: add some rocky texture between the grass and the road of dirt. In between rocks and the terrain there can be grass or smaller rocks with a different texture to make the transition smoother too.

In here I'd comment that technology is a limiting factor because some older tech won't be able to have multiple layers of textures and blend them with transitions. The solution for such cases is to pre render the texture's layers, merging them on one texture. In case there are severe memory constrains there isn't much room for large and/or multiple textures.

Rocks. In here Hourences makes an interesting statement about feelings, atmosphere and how that connects to the shape of rocks. If you think about harsh weather conditions strong winds and storms for example. The rocks are probably going to have more rounded shapes and more trails where the water flows down. If this is an MMORPG this ties in with the types of enemies the player is going to encounter there. Smoother would equate to easier. Now think about aggression. Spiky mountains would feel more aggressive. The enemies in the area would be more aggressive to match that atmosphere. If I stretch this concept of shapes and atmosphere a bit I can relate it to the graphs that Hourences made to explain contrast. Smoother graphs vs Rougher graphs would equate to friendliness vs unfriendliness.

About natural looking rocks the first thing that I'd look for is for pictures of real world landscapes. I'd pay attention to weathering processes and gravity. Rock formations where there is a lot of fractures, cracking, landslides and other erosion processes are good places to start from.

Horizon. This is pretty simple. Avoid cutting off the world's edges like a sharp knife cutting meat. Mountains that have nothing behind but void should be avoided. In here I'd like to comment that this is also a technological limitation. Sometimes the hardware cannot handle rendering open vistas and concessions have to be made.

Sky. Again, technological limitations mean that the game won't be able to produce any type of sky. The hardest limitation is that it's not easy to render realtime dynamic weather. Static weather on the other hand is easier because we can rely on static paintings. The most obvious mistakes here regard color and time of day. If there is a thick cloud cover the ambient lighting can't be very bright. If the sun is shinning from the South, the shadows on the ground have to match that. Else it's going to look fake and wrong. The sky must have clouds, moon, stars to convey emotions too. If it contains nothing but a single color it becomes boring, unless it was intended.

Textures. The most glaring mistake is to have misaligned and/or wrong scaling. Another mistake is to mismatch textures, such as clean floor with dirty walls, or different styles that shouldn't be used together. In here I'd add that sometimes the storyline can have excuses for that. We do have some degree of freedom, but at the same time freedom doesn't mean arbitrary choices. One way, maybe the strongest way, to keep textures under a common theme is to use a limited color palette. It doesn't mean that all textures from a certain group should share the same colors, but that they obey to some style. An example of this is Star Wars. The textures regarding the empire always have a predominance of white, black and grey.

Hourences tells that one often overlooked property of textures is brightness and saturation. When an artist makes a texture it's displayed on screen without interference from lights. However, in game, there is lighting and the light has color and brightness. Textures have to account for different lighting conditions. Programmable post processing can do something about textures and light, but better solve those issues at the origin than trying to rely on post processing to fix it.

Materials. With the ever advancing technology textures are closer to real life materials. We can control properties such as how much light it reflects, how much light it absorbs, how much smoother or rougher it is. This means that more power brings more responsibilities and more complexity. Reflectance, transmittance and other properties dictate the environment's mood because materials convey coldness, warmth, receptiveness, neglection, etc.

Textures and light

Light is also associated with emotions and pretty much everyone learns this intuitively. In a broader concept we have waves and both light and sound are waves, which means that sound and light shares very similar wave's properties. In here I'd like to comment that some people, for different reasons, may not feel the same under the same lighting or auditory conditions. There are certainly some cultural differences when we compare the color choices among different countries, but I'm not going to discuss that.

Source. Every light must have a source. In here I'd like to comment that sometimes this rule can be broken. In older Tom Raider games there is light underwater without any sources. This is physically wrong, but it doesn't look wrong in the game because it was an artistic choice and/or a technological limitation. It's pretty common for movies to alter the environment's brightness for artistic reasons. In Horror movies for example or during night scenes, there is a blue ambient light that is artificial but it's done that way because without light we can't see anything. An example of this is Alan Wake. All night scenes have an ambient light that doesn't match the real moonlight, but we have an artistic choice here. In this site I have given examples of bad lighting.

Lighting composition. Pretty much the same discussion about contrast in regards to geometry and textures. We have guiding lines with textures and geometry. Light also has the power to guide the player's attention and to create shapes by means of contrast.

Light's colors. Hourences makes a pretty good explanation here in regards to color systems. With light we have two opposite extremes: full bright and full dark, which translates to white and black. When we see something what we see is light being reflected and when light is reflected off a surface it contains information of it. Either there is light being reflected or no light at all. Black light doesn't exist because black is the absence of light itself. That's why we always add light to the world, unless there is some weird engine out there where we subtract light from the space. On the other hand, textures use a color system where the basic colors are not the same used for lights. The resulting confusion is that some colors, counter-intuitively, are non existent in lights. For example: gray light doesn't exist. What exists is white light that is more intense or less intense.

Unfortunately I think that most teachers never explain the differences at school and we are often left with an incomplete comprehension of colors and light. We always learn that there are three basic colors and mixing them in equal parts should result in white. However, how do we combine colors to result in black? That's the error! Black is not a combination of colors, but the absence of all colors! Any surface under the absence of light is going to be black no matter what color it is.

When we want to make surfaces darker we have to make the texture itself darker. Because lowering the light's brightness is going to make the whole space darker. If I were to explain this using physics I'd say that to make a surface darker means to change how much light it reflects and how much light it absorbs. In here I'd add that if we have a conflict between a lighting artist, a texture artist and a level designer, we have a problem.

Lighting composition. Hourences uses the same graph to discuss that lack of contrast and excessive contrast are to be avoided. This discussion can be very long because when it comes to light and contrast, there are two main types of contrast: intensity and colors. For example: black and white create the most extreme contrast of all. Yellow and red creates less contrast than red and blue. But we can always have contrast in the form of increasing or decreasing saturation too. Add in size, radius, number of lights, placement, alignment and there are literally thousands of different ways to compose lights.

About emotions there are certainly scientific research in this area relating to multiple fields. Hourences advocates against running away from clichés. For example: all pictures of the Sahara desert show the predominance of yellow, brown, orange, colors; all pictures of the Antartic land show the predominance of blue, white and grey. We can be creative, but at the same time, if we forget about clichés, we may end up with a lighting mood that doesn't match the emotions that we want to convey.

The last topic about lights that Hourences discusses regards realism. First, photorealism as in renders that take hours to complete is almost never a good idea. Think about movies, they always change lighting in a way or another due to the artistic choices made. Second, there isn't enough processing power to simulate light with complete physical accuracy. I'd say that we don't need to. The main issue here is about design and/or arts. Shadows, brightness, saturation, colors, contrast, all that depends more on designing and artistic choices than on technology itself.

Audio

Audio designers exist for a reason. In the past, with severe hardware limitations, sound was often left for simple sounds with no care taken about creating immersion, depth, conveying emotions, etc. That's no longer the case with games using complete soundtracks with great care taken to convey emotions. The same discussion about contrast, intensity, ambience, etc that is made with light and textures applies to sound as well. After all, both light and sound are waves that obey to the same physics. The most important difference is that light is much faster than sound and with the exception of deaf people, light takes precedence over sound.

Hourences makes a distinction between ambient and detail sound. The former is sound that doesn't have a clear or visible source, such as wind or creaking sounds from large constructions. The latter are sounds with clear and visible sources such as waterfalls, machinery or animals. Whenever you can, put those sounds in your level because they add depth and help create a more living world. I'd add that there is an issue here related to the propagation of sound. With light the hard part is adding indirect light because it's incredible expensive to calculate it. With sound old games tend to completely disregard occlusion, meaning that sounds propagate through geometry with no calculations performed in regards to absorption and transmission.

There isn't much in the book about sound. The most basic discussion that book makes is about the importance of variation. We can easily recognize when multiple sounds are exact copies of one another because the repetition is an easy pattern to recognize. In here we also have a technological limitation because there isn't enough memory or processing power, or human resources, to produce unique sounds for everything.

In the same way there can be excessive contrast of light, we can have excessive contrast of sound. Too many different sounds playing at the same time is confusing. And they can also have an unwanted additive power, making the environment too loud. In the real world we have to turn off machines, remove animals from the place or stop the water flow to turn off the sound. In games we have the luxury to have control over sound, light, behaviours and geometry all separated from one and another. Take advantage of this.

End

The final part of the book discusses atmosphere and immersion from a storyline's standpoint. To summarize it, it's the culmination of everything that the book discusses in the previous chapters. All the discussion about light, textures, geometry, architecture, gameplay and sound is made from a technical point of view. In this site I've given many many examples about atmosphere and storytelling.

One last comment that Hourences made is that multiplayer levels can and should have storylines, in contrary to what lots of people would say. This is really hard to achieve because multiplayer levels have different goals. One example would be Bioshock 2. The multiplayer part is not just a bunch of multiplayer levels detached from the single player storyline. They took some effort to explain that the players are placed during a time period of a civil war that is part of the Bioshock's universe. Another example would be Movie Battles II, a mod for Jedi Academy that attempts to bring the battles seen in the movies to the game. Allowing the players to experience events from the movies by playing them. This is a very hard task to successfully accomplish because we have different demands for single player and multiplayer. Different weapons, different settings and different perspectives.

The extras in the book are interviews and some in depth analysis of Hourence's own levels.