The past few months I have been doing research in the level flow and environment design in games like Uncharted 4 and The Last of Us. With this blog, I wish to show you my findings and explain my idea of what level flow is, the different elements of level flow and how level designers use them to make informed decisions about their level design...

When the player knows what to do, where to go. But not always know how to achieve or get towards that goal. (keyword: Spatial Awareness)

It is a state where the player has a smooth experience, traversing through the level. It goes hand in hand with game flow. This definition is quite vague and that is because level flow is a broad subject. For simplicity I like to split up "Level Flow" into four (4) smaller pieces. In high level terms, these are some of the elements we level designers use to guide the player(s).

I need to know about geometry and composition? But I am not an architect or artist?!

Yes, I am also not an artist or architect, but I believe that everything is in some way intertwined with level design. Mastering small bits about these subjects will allow you to make more informed design decisions. It will allow you to make levels that look good, feel natural and play well. Perhaps it is time to read through an architectural book. I could highly recommend the book from Francis Ching:, Architecture: Form, Space and Order.

Geometry, composition, scripted events can be combined to create storytelling elements. Being able to masterfully use each of these components will allow you to guide and move the player to where ever you desire them to go.

Lines, arrows, shape, silhouettes, pathways, etc.
Lines have two points, a beginning and an endpoint. A line affords direction. It is a 2D entity that moves in a direction. We can see lines as arrows and arrows afford direction.

In the example below, multiple objects in the scene will hint towards this focal point, the mega structure.
The single pathway but also the contrast, the shape and atmospheric effect in the environment creates a tunnel like effect. Guiding the players eye towards the landmark. Geometry and Composition creates these guiding lines.

They help to guide the players eye from A to B and visa versa. The player knows which direction they need to go.

Uncharted 4 - Join me in Paradise
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1) Nathan Drake talking and pointing at the general area they want to explore
2) The pathway that gets created due to the way the houses are placed
3) The slope of the mountains guide the players eye towards the landmark
4) The contrast between the mountains and the forest through color and atmospheric effects
5) The way the houses are placed down and the roofs angled.

It all creates a valley like composition where you funnel the player through the gameplay space.

A game scene is like a 3D canvas where the level designer is the painter and the viewer is the player.

A landmark is an object or feature of a landscape or town that is easily seen and recognized from a distance, especially one that enables the player to establish their location on the map.

Landmarks can be used to determine someone's location, approximately from the landmark. Therefore it is a method to improve flow in the level. An exceptional level designer would work together with the environment artists, to make sure that each area is recognizable. They should work together to determine the line of sight and the visual language of the area.

The Last of Us - Pittsburgh
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In the example above, Joel is able to see the bridge from multiple angles. This allows the level designer to create a level that doesn't go into a linear/straight direction. As walking straight towards the objective is boring and no fun. Even if the level plays out linear, we can fake the feeling of it being an "open world".

The high buildings on the side also helps to frame the bridge, funneling the player towards the objective. The only indication the player needs to know is how far away they are from the bridge. If they are approaching closer to the bridge, they can assume that they are going towards the right direction.

Using Color as Affordance: Color can be used to indicate the player, that a certain object is able to afford something. It can be used to contrast the scene, shifting the focal point.

Uncharted 4
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In this example, all reachable & climbable ledges have these "light yellowish" color casted on them. Informing the player that those afford to be grabbed/climbed. This is a clever way to indicate something to the player, without it breaking the immersion. By blending in with the cliffs, using the same "earthly" tones.
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You can also use color and lighting to create a mood. which invokes an emotion from the player. Bright shades of red and yellow and a dark claustrophobic alleyway might indicate danger , while a well lit open area with plants, lake and a group of deer's can make you feel like its a safe space.

Repetition is beautiful, as humans can see and recognize patterns. Nature is build up out of patterns, the geometrical shapes that form into perfect patterns feel almost unnatural.

Patterns, repeating a level flow element, will instinctively remind the player of the place where they previously saw them.

But when you repeat it too often, it becomes boring. You can compare it to listening to the same song for 100x times. At first you might like the song, although after repeatedly listening to it, you might come to dislike it. This problem is also true in level/environment design. Do not let the player(s) traverse through areas that all look the same. What is the point of exploring if everything looks the same? You can keep it look coherent, but be sure to have a bit of variation. As mentioned in the previous point: Mood, Atmosphere / Color is a nice way to break up the monotone feel of a scene and to attract the players attention.

Do you know the way? Do you know where you need to go?

clip: 0:00 - 1:00 (You can watch the entire video if you like)
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Uncharted 4 - Infernal Place | Prison Escape Scene
In this example: Nathan breaks out of prison with two of his comrades. In this action packed scene, your goal is to escape the prison. The player can experience this scene as stressful and rushed. You aren't prepared for this. You don't even know the layout of the prison and now you have to make a break for it! During this moment, the player doesn't want to constantly think about where they need to go and accidently get lost. This is where the two side characters take it over and guide you through the scene.

Somehow the two side characters do know the layout of the prison. You just have to follow them and escape the place.

I don't know where to go, guess I follow everyone else.

The clip below is another example of movement being used. Similar to the previous example, the player is confronted with a high intensive experience. Where "yet again" the goal is to escape from the mess you're in.

clip: 10:30 - 13:30 (Joel & Co running away, following the crowd)

The Last of Us - Prologue |Escape the City Scene
In all the chaos you don't know where to go, so you follow the crowd. Where ever they go, you will follow. Your only goal is to get out and keep Sarah safe. The crowd is moved by "seemingly" uncontrollable events in the scene. An exploding car would drive the crowd to the opposite direction, towards... well non-exploding cars.

It doesn't have to be complicated. The previous two examples requires the developers to create AI with a behavior system. Although that could be really cool, it's also complicated.

clip: 42:18 - 42:30 (Swan flying away)

The Last of Us - Bills Town
A subtle tumble weed rolling in a certain direction or in this example; a swan flying away into the distance. It hints to the player to keep moving in "that" direction. It is subtle but it adds to the overall experience.

Flow can also be created through storytelling elements. If they are signs, text, voice over, detail decals and even meshes that are placed and rotated in a certain way to guide the player.

In the example above, notice how the tank is placed. Due to how the tank is angled 45 degrees, it naturally guides the player towards the left side. The tank is used as a physical barrier/obstacle to guide the player to the left. Some level designers like to occasionally put objects in corners to get rid of that 90 degree angle. By placing an object there to make a 45-ish degree angle, the player physically gets pushed out of the corner and doesn't face plant against the wall.

Signs will tell you where to go. The left billboard reads: "Medical Evacuation, Use Tunnel" while the right billboard reads "Salt Lake City, Military Zone Ahead". The military billboard is a sign to the player that they need to be careful. It forecasts the player what might happen in the future. Players that pay attention to these detail will adapt their playstyle and approach certain situations differently, affecting the flow and momentum.

Next to the obvious fact that the player only can go one direction due to the layout of the level, we can use these additional elements to convince / strengthen the players believe to follow that specific pathway, without them questioning why it is blocked.

Another example is to use breadcrumbs to assist the player through the level. It can be a way to indicate the player that they are on the right path. In this example, bricks are scattered around the area that the player can use to take out the enemies.

Personally I think the level should be able to be understood without use of bread crumbling. But it is definitely an additional tool to guide the player.

3D levels are created in... 3D

It is less complex to make a 2D picture look nice from one angle than making a 3D world look good from all angles. But in 3D games where the player can freely roam around and explore, they usually have multiple views on an object. The level designer and the environment artists can make everything look nice, but they probably don't have all the time of the world to make it perfect. However, as a level designer one can plan ahead and make sure to get the most out of the level, by setting up rules and boundaries in advance.

Limit the views the player can have, limit the places that players can reach while still maintaining the open world feeling of the game. Pay detail to the more important aspects. What do you want the player to see? Try out different lighting setups.

Guide the player through the map with use of flow elements! Make the chances that the player wants to go off-track unlikely! Don't place landmarks at spots where you don't want the player to go to. Uncharted 4 levels feel very open. But secretly their levels are linear, with a golden path.

There is no incentive to go off road if there is nothing there anyways... oh look a cool mountain!

The player can move around? No problem, we can still frame the shot, just press this button!

With a press on a button (L3), the developers allow the player camera to momentarily reposition itself, aiming at the point of interest. Using this method they frame the shot, giving them total control on what they want the player to see.

To pack it up and review what we have observed. Lets breakdown the gameplay of one of the sections in Uncharted 4. We will analyze a particular section in Chapter 2: Infernal Place. We will review the gameplay down below.

I chose this section as it caught my attention with how the developers setup this area. I reviewed other playthrough content of this exact same area and it seems like other players were experiencing the same thing as I did. Making me thing that it was not a coincidence.

Nathan doesn't have a map, he doesn't use a compass. What a badass.

clip: 8:55 - 10:35

Uncharted 4 - Infernal Place

1) The player sees a tower and grapple hook his way towards it.
2) He proceeds to climb up the tower with use of the grooves.
3) Climbs inside of the tower.
4) Walks around the plateau.
5) Almost falls into the ocean, trying to find a pathway.
6) You can see that the player is confused about where to go and even questions if they have to move downwards.
7) After re-assessing the situation they put 2+2 together.

Can you recognize what went on in this small section? What do you think caused the confusion by the player? Was the player misinformed, weren't there enough flow elements? To my observation, they placed a lot of flow elements to guide the player but because of a few unfortunate elements. It unintentionally outweighed the other flow elements placed by the designers.

Lets look at all the elements and assess the situation of what might have caused this situation.

There were a few cues that should had helped the player

Direction: This wooden bar seemed to afford to be hooked. It in fact does not but it does point towards the objective!

Direction and Shape Language: A pointy triangular rock. Points & triangles can be seen as arrows, arrows indicate direction. In this case this rock is telling us to go upwards.

Color: These grooves have a light yellow rim. In example 2.3, I explained that Uncharted 4 likes to use color to indicate towards the player, in this case it tells the player that it affords to be climbed on. It is a tiny bit difficult to see as the light is shining right on top of them.

Text & Speech: Nathan knows something you don't know. "Onward and Upward" he says. He hints to keep going up. This is a critical cue that tells the player they should continue upwards..

With all those flow elements, what made the players confused?

I believe the main reason for the confusion was caused by the two following elements.

The door way and the wooden balcony.

When we convert the picture to black and white, to view the values. We can see that the difference in contrast makes your eyes focused on the doorway and the wooden platform. The doorway affords to be walked through, gates are strong methods of guiding the player. They have a strong attraction to them. You want to walk through it to see what's on the other side. The imbalance between the contrast in shape, lighting and color made the doorway and wooden platform pop out more than intended.
For the wooden platform, the object shape is also an irregularity as its sticking out from the tower. It is like an invitation to stand on.

I believe this is what confused some players.

Luckily when the player decides to respawn to the previous checkpoint. The players camera will be positioned in a way that makes it clear where they need to go. It is not ideal but it is also not a blocker.

What would you do to make sure players get less confused? Do you think the developers could have tried something different?
Highlight the grooves a bit more? Playing around with the lighting and shadows so that the tower would be contrasted with the background? Nonetheless, without changing anything, the player can also jump of the cliff and the game would respawn the player on a spot with a nice view of the tower. Was it planned or was it a band-aid measure?

Was it planned or was it a band-aid measure?

I don't know the actual intention of this mission beat. Everything I say is based on my observation, in which we could formulate a hypothesis. It is fairly possible that this beat was suppose to play out like this. Making it a bit difficult for the player to spot what they had to do next, with the extended terrain, allowing them to assess the situation and make up a plan on what to do next. A moment to change up the pace, a moment where the player could relax but also a moment to hint towards the player that it is important to look around to find clues and hidden treasures. We might never know the real intentions and that is okay, design is about evaluating risk & reward, every scenario is different.

Stop looking into it too much, it doesn't have any meaning or reason for why it is done this way

Maybe I am looking too much into it. Maybe I suffer from Blue curtain reasoning, trying to find symbolistic meaning and the connections behind the color and shape of objects. From my perspective there has to be a reason why something is placed at the position its at. Otherwise it might as well not exist. Does it have a deeper meaning or did the developer just placed it there because they thought it looked cool there? Only the person that made that decision can answer that question.

Disclaimer: At the time of writing this article I am a 4th year level design student at Breda University of Applied Science
(NHTV / BUAS). I have no affiliation with Naughty Dog. This research is my own take on the findings I have done. Gameplay footage of other players were used in this article for educational purposes.

Since 2021, I have rewritten part of this article as my point of view has slightly changed. I thought it was only fair to update it and refine my sentences to make sure my thoughts are well explained. Reading back at what I wrote, I felt like my choice of words could have been better. The articles on the other websites won't be updates as I don't have the capability to change them as this article got copied & re-published by their site owners. Feel free to share the link to this article with your peers if you liked it.

Thank you for reading!