the artistry and psychology of gaming


The Architecture of Half-Life 2 (Part 3)

The Architecture of Half-Life 2 (Part 3)

Welcome back to the third and final part of our analysis of Half-Life 2‘s level design. You can click on these links to read Part 1 and Part 2. This week we’ll discuss aesthetic details, then wrap things up with a few broad concepts like variety and the ability of the developers to guide the player.


Another important facet of level design is aesthetic presentation. I generally won’t spend much time discussing beautiful levels; we have another feature for that. If there is symbolism in the environment, or if something else about the aesthetics is particularly noteworthy, I will probably elaborate on that. For what it’s worth, Half-Life 2 still looks very pretty, and there is a lot of attention to detail in the environments. Granted, it may not seem like much in the wake of games like BioShock, Uncharted 2, or Alan Wake. However if you manage to get to an area of Half-Life 2 that the developers didn’t expect you to see, you’ll notice that it’s a lot more empty and less visually interesting than the rest of the game, and you’ll recognize how much effort went into making the environments aesthetically appealing. Beyond the basic visual presentation, I would also like to discuss two other aspects related to aesthetics: atmosphere and world building.


When used in the right combination, audio and visual clues can make a game much more immersive, turning it into more of a visceral experience. Lighting, sound effects, little details in the environment – all of those and more contribute to building atmosphere. Most of the time, this is used to instill a sense of fear or dread in the player (which is why Ravenholm is probably the part of Half-Life 2 you’re thinking about right now), but atmosphere can be built around just about any emotion.

We don’t go to Ravenholm.

There are many other areas of the game that utilize atmosphere just as well. I mentioned in Part 2 that putting a huge set piece at the beginning is a great way to start a game. Half-Life 2 does not begin this way, but there is a reason why many consider it to be one of the greatest openings in video game history, alongside action-packed games like Contra III, Medal of Honor: Frontline and God of War [insert number here]. From the moment you step off the train into City 17, you are almost overwhelmed by the oppressive nature of the Combine’s regime. Half-Life 2 takes place in the Orwellian style of dystopian future, and everything – from the ubiquitous masked Civil Protection officers (read: Thought Police) to the imposing Eastern European architecture to the dejected jumpsuit-clad populace – adds to that suffocating feeling. The atmosphere draws you in from the very beginning.

Big Broth- I mean, Dr. Breen is watching.

Another incredibly atmospheric moment occurs toward the end of the Highway 17 chapter. You need to cross a large railway bridge, but a force field blocks your path. To deactivate it, you must maneuver across the supports underneath the bridge, fighting enemies along the way. This would be terrifying enough on its own (partially because this is one of the only platforming segments where failure means instant death), but the details added by the developers are enough to give you vertigo. Every so often, a train will speed across the bridge, making the entire level quake and causing a cacophonous rumble to echo through the bridge supports. Valve takes what could be a series of fairly generic firefights and turns it into a very intense experience.

I don’t ever want to feel like I did that day.

Also contributing to the atmosphere of Half-Life 2 is the fact that passage of time is taken into consideration. The game begins during the daytime, but the sun starts to set during the Water Hazard chapter, and by the time you get to Ravenholm, it is nighttime. Many games have levels that take part during different times of day, but HL2 is a continuous experience (barring one jump in time about 2/3 of the way through the story). The game contains no in-game clock to govern the day/night cycle, meaning that the time of day at any point in the game is exactly what the developers intended. I’ve always been fascinated by games that portray the passage of time without interrupting the game or featuring an in-game clock. There was a level in Donkey Kong Country 2 where the sun set as you progressed, as well. Half-Life 2 takes place over the course of three days, though the third does not immediately follow the first two.

World Building

World building is the process of constructing a coherent setting with its own history, culture, ecology, etc. Specifically, I will be focusing on how this setting is presented, particularly during gameplay. Not every game needs to be great at world building; in fact, if a game does not make world building a priority, I won’t fault if for that. I don’t really care if all of the monsters in Doom exist for no other reason than to catch my shotgun shells with their faces. But if a game puts a lot of effort into world building and does an excellent job of it, that deserves recognition.

I’ve already mentioned the many scripted events, the bleak opening, and the indication of the passing of time – all of which contribute to creating the unique Half-Life universe – so for now, I’d like to point out something a little bit more specific. Meet the Consoling Couple.


They appear twice (possibly three times*) in Half-Life 2 and once in each of the Episodes. Every time you see them, they are on the same couch in the same pose, but their topic of conversation changes depending on the circumstances. Valve designer Marc Laidlaw included them because he liked the idea of self-contained characters “caught in a loop,” independent of the player’s actions. Their story doesn’t necessarily begin when you select New Game, and it doesn’t necessarily end when you reach the credits. Even though their unchanging posture is more or less an in-joke, their presence still serves to suggest that there is more to the Half-Life universe than Gordon Freeman’s personal social circle. By the way, do you know what inspired Laidlaw to include these characters?

Honey and Darling from The Legend of Zelda: Ocarina of Time/Majora’s Mask.

*Shortly into the Route Kanal chapter, you encounter a couple being harassed by two Civil Protection officers. This couple uses the same models and voice actors as the Consoling Couple, but it is unsure if they are canonically the same people. If they are, this is the only time they aren’t found on their couch.

Disguising Technical Limitations

Despite the fact that technology is advancing at an exponential rate, computers still do not possess infinite processing power. Video game worlds cannot extend forever, so determining where and how the gamespace ends is up to the level designer. Popular means of corralling the player include physical walls, sheer cliff faces (or very steep hills with no friction), deep chasms (sometimes known as gravity barriers), unclearable piles of debris, broken bridges, large stretches of water (particularly if the player character lacks the ability to swim), or monsters/obstacles that will kill the player should they stray too far from the beaten path (like a grue). The Insurmountable Waist-Height Fence is also rather popular, though it tends to infuriate gamers who expect to be able to simply jump over it. Invisible walls are likewise seen as lazy.

Even with a finite gamespace, exceedingly few games can load the entire game world at the same time. While an entire game can fit on a disc, only so much data can be loaded into the hardware’s RAM at any given point. One solution to this problem is to simply put up a loading screen as the next area of the game is being loaded. However, more and more games are utilizing dynamic loading (i.e. loading each part of the game on the fly, shortly before the player reaches it) to streamline the player’s experience and open the possibilities for much larger levels. Clever level design can actually be used to aid the process of dynamic loading. Remember when I talked about space-filling paths, and how they could keep you in a certain area for longer than if you simply were able to run to the exit door? This also gives the next area more time to load. Another common tactic is to force the player through a long, narrow, winding tunnel. About halfway through the tunnel, the game will dump the memory from the previous room and load the next one, unseen by the player. In some games, you can still manage to “outrun” the dynamic loading, at which point you’ll usually get a more traditional loading screen. If you’ve ever played Metroid Prime and had to wait a second or two for a door to open (usually while Space Pirates are shooting at you), that’s because the next room was still loading.

I may be wrong, but I don’t think Half-Life 2 utilizes dynamic loading in that way. There are points where the game displays a loading screen, and I believe the entirety of the next section of the game is loaded at that point. However, most of these loading screens happen inside or in a tunnel, which has a different benefit. This lets them change the skybox without the player noticing, meaning that the passage of time seems more gradual. However, whenever they change the time of day during a loading screen, there is always a one-way obstacle (often called a “Sawtooth” in game design parlance) keeping the player from returning to the previous area and effectively going back in time.


Variety is related to pretty much everything I’ve discussed so far. If a game remains static throughout the entire playthrough, it becomes a tedious chore instead of entertainment. I’m not saying that a game needs to be loaded with vehicle sections and minigames or it becomes boring; a developer can simply take the same tools used to make one part of the game and use them in a different way to make the next part.

Valve understands variety. Sure, there are a couple of vehicle segments, but more importantly, almost every chapter of the game introduces some new idea or challenge. Not only that, but the level design in that section will deliberately highlight the new concept. In the Sandtraps chapter, the developers introduce monsters (antlions) that spawn whenever you step onto the sand. Instead of just making you run across the sand every so often to make antlions appear, they give you a choice: make a mad dash across the sand and fight/outrun a constantly spawning flood of monsters, or jump across a series of precarious stepping stones to avoid the antlions altogether. (The Orange Box update even added an Achievement for completing that section of the game without touching the sand at all.) After a while, they take away the solid ground, but leave a bunch of debris scattered about, so you can make your own stepping stones with the Gravity Gun. Other chapters focus on different ideas, like defending a position with turrets or leading a squad of rebels.

The Episodes also introduce new ideas, making them true expansions instead of rote rehashes of previously released material. Episode One encourages cooperating with your AI partner, Alyx Vance. (Don’t worry – she is much more reliable than Sheva Alomar.) Due to an ammo shortage throughout the game, you’ll find yourself relying on Alyx and her bottomless supply of clips. Likewise, she will rely on your flashlight in dark areas. Episode Two features more large, open outdoor environments and includes a new vehicle and a new, larger, more agile type of enemy.

Guiding the Player

With graphics improving and environments becoming much more detailed, it can be hard to notice the way forward at times. Sometimes, level design can even be used to guide the player. There may be subtle hints in the environment that indicate where to stand, where to jump, what actions to take, etc. For example, in many action games (particularly those that take place in an open world), most doors only serve as decoration and can never be opened. If a mission requires the player to go through a specific door, level designers will often make that door stand out in some way, at least at a subconscious level. If they don’t want to break immersion by making the door glow unnaturally or placing a waypoint on it, they may make the door a color that more strongly contrasts with the surrounding walls. If the mission takes place at night, it may be the only door with a light above it. Guiding also extends to making sure the player doesn’t accidentally get distracted by things that aren’t important.

If you’ve ever played a Valve game with the commentary on, you know that they do extensive playtesting. They observe the way that regular people play their games, scrutinizing to an almost obsessive level, and then they tweak the game to help it flow better. Many times the developers will comment on how the playtesters mistakenly thought that some irrelevant piece of scenery was an essential piece to a puzzle, and they will detail how they altered the game to make sure the misunderstanding doesn’t happen again. They also hint at particularly effective combat strategies against certain enemies. Sometimes these hints are obvious: in Episode Two, Adam Baldwin outright tells the “AR3 Guy” (and by extension, you) that the secondary fire of the AR2 pulse rifle is extremely effective against Hunters. Other times, the hints are more subtle. Snipers hide in windows and can only be defeated by throwing a grenade (or shooting a rocket) into the window. The first sniper you encounter has a box of grenades sitting right below him. (Also, whenever an area has snipers, the first one will always be shooting at something else, like zombies or birds, to give you a fair warning.) The Ravenholm chapter also includes a hint as to the best way to defeat the enemies in that level.

I think they’re trying to tell me something here.


While guiding the player can improve the flow of a game, sometimes it’s best to give them the freedom to solve problems in their own way. Different people have different playstyles, and some developers design their levels to allow multiple solutions. Half-Life 2 grants the player some freedom, but not much. I already mentioned that there are two viable ways to play the Sandtraps chapter, and the Gravity Gun also opens new possibilities. However, the game is still rigidly linear. For an example of a game in which the level design allows and encourages freedom of choice… well, you’ll just have to check back next week.

This concludes my introduction to the many facets of level design, as well as my analysis of the level design in Half-Life 2. Hopefully you will walk away with a newfound admiration for the science of level design, as well as the men and women who excel at building virtual worlds (like the good folks at Valve). From this point forward, I will be covering a new game every week, from platformers to shooters, from hack-n-slash titles to racing games. For now, enjoy this screenshot that didn’t logically fit anywhere else in the article.

Included by Gabe Newell, in response to the Half-Life references during the early seasons of the TV show Lost.

One Comment

  1. not a huge fan of reading articles online which have over 3 paragraphs… but this article was just amazing! :)… love it!

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