Looking back at Portal and it's Learning System

Until recently, I wasn't sure what my particular compulsion and driving force for playing a game was. I play a multitude of games of course; and I try very hard to finish most games I play, mainly due to having spent the money on it. So I always try to make the most out of what I'm playing even if I'm not necessarily enjoying it, but I tend to know what I am going to enjoy. Most games I've found that I do enjoy, create a strong iteration process to keep me invested. And I've similarly found that; Designing Iterative mechanics is what I excel at best. It's with this in mind that I visit one of my personal favourite games for both general puzzle design and iterative design, Portal. 

Portal is a first-person puzzle game. In Portal, the player is given a tool called the Aperture Science Handheld Portal Device (or Portal Gun). The Portal Gun can project 2 opposing sides of a doorway, which allow the player to teleport across any visible distance within a 3 dimensional space. The game is presented as multiple test chambers within a laboratory. Each new test chamber has a new puzzle for the player to solve, using the portal gun. The game features an overarching comical storyline where the player’s avatar Chell; is being coerced into doing these puzzles by a sentient robot called GlaDos, with the promise of having cake at the end.

The player is given a rewarding learning system, where they are educated in practice and never told what to do. The basics are taught entirely through the game and level design. The Portal Gun itself, can project both ends of a doorway, though the player learns that the portals don’t simply carry objects through. The game features a complex physics mechanic; so that any force acting upon the player (or an object), is carried through the portals also. This starts with placing cubes upon pressure sensitive pads and culminates with using gravity and an imaginative use of portals; to gain extreme velocity, which propels the player (or objects) through the air. Over the course of the game, the player is continuously taught new rules and exploits to these mechanics. Consequently, the player is only ever given the tools to succeed. This is constantly shown to the player through feedback in the environment. Everything in each test chamber is there for a reason and once the player figures out how all the pieces fit together, they will have solved the puzzle. However, these effortless mechanics usually become complex in execution; when the player is relying on being instinctive and doing multiple versions of these mechanics in one swift movement. This is when Portal is at its exceptional (and perplexing) best.

The entire of Portal could be seen as a tutorial in a traditional system. This is because; the player is only ever learning new techniques to solve puzzles. The learning methods of Portal make it unique in this way. This is expertly crafted in the early levels, as the game makes it near impossible to not solve the puzzle, despite offering new circumstances every time and despite never revealing any hints (like on screen text or video). The feedback in the environment is all the player ever needs to be able to solve the puzzle, as everything in the test chambers is there for a reason. For instance, it’s very important to help the player understand how the portals work without actually telling them. Thus, the first time you enter a portal, it’s clear that the portals are indeed portals and not simply a tunnel. This principle is further conceived when the player can see themselves within a portal, as the opposite faces them. The player then must walk around that same room and see that there is no possible way that it can be nothing other than a teleportation device, as the portals have no rear.

The early levels are very simple in practice but are actually excellent in implementation. This is because, it’s difficult for the player to play wrong and get stuck. They’re never told exactly what each object does, but rather subtly influenced through previous solutions. In the opening 10 test chambers, the player learns that:-

• The portals can be used to traverse impossible distances, 
• The portals are equal parts of the same doorway (ensuring that the player can choose to walk through either end), 
• The portals can be placed on any plane as long as it has a white surface (all early levels have white walls, ceilings and floors), 
• The portals cannot be placed upon black planes (this colour pallet also makes it easily distinguishable at a distance), 
• The cubes can be picked up and placed upon switches to open doorways, move platforms and/or activate machinery, 
• The portals can be used to teleport more than just the player (objects such as cubes and light pellets), 
• The momentum acting upon the player (or an object) as they enter a portal is equal to that which is carried out the opposite side, 
• Light pellets can rebound continuously off any surface and are also required to activate doorways or platforms, 
• Walking through a lift is required to complete a puzzle and when the player does, it eliminates the use of portals and removes any existing portals, 
• They cannot be hurt from falling. 

None of these rules are ever taught to the player. Instead, the player learns that they are ultimately the only solution or indicated through environmental feedback. This natural education really helps the player understand the rules of play within the space of Portal.

Additionally, in these opening test chambers, the player is only armed with the ability to shoot one side of the portal. This is firstly to limit the control of the player within the room, but also that they may learn that both ends of the portal are also the entrance. For this logic, it may seem that it would have been useful to colour both portals the same. But in fact, some puzzles require the player to know which portal is placed where (should the player need to move from A to B to C quickly; A and C’s portal will need to be of the same colour), so it is more important that the player can associate a coloured portal with a button. In this case, the left mouse button shoots the blue portal. But there’s a lot of colour co-ordination for the player to associate with in the game. For instance, the test chambers and turrets are in black and white. This is while most of what the player can influence will have a colour, such as blue and yellow for the portals, orange for the player avatar and red for the switches.

In this same approach, Portal’s feedback often over-emphasizes important features, despite the already basic layout. This is clearly to identify their significance to the player. For example:-

• Most objects in the game are unnecessarily large, such as the cubes and switches, 
• Switches are on raised ground and have dotted lines that point to their corresponding use, 
• The clear indication of black and white in a test chamber usually dictates how the player will move through it. For example, the player will realize that a white plane amongst black planes is crucial to the puzzle. In the same way, that a black plane amongst white is limiting the use for a reason, 
• Glass panels are to help the player see a section of the room without being able to directly influence it at that moment, 
• Large test chambers will usually require the player to launch themselves across the room. 

In practice, the first time the player is required to use momentum to project through the air (or flinging as it is referred to); they enter into a test with dark tiles everywhere. Immediately, the player’s attention is drawn to look upwards as the wall above them starts to move forward on a mechanical arm. This wall is white allowing the player to shoot the blue portal on to it. In front of the player, a large descent where at its base, is the corresponding yellow portal. As there are no other options or directions to go; the player’s only destination is down. When dropping the player can see through air resistance in the view; that they are gaining velocity as gravity pulls them towards the ground. The player hits the portal and is carried out the opposite side with enough momentum; to cross the descent they just jumped down. The player then has to do this a second time, as another wall as been brought forward, now at a slight curve. This time the jump is a greater distance, as is the drop below. The player will see that not only does the curve project them in an upward trajectory, but also at a faster rate.

Again, there is no indication to the player how to solve this puzzle. It, at this early stage, is simply the only possible solution for the player - the only wall that the portals can be placed and the only direction that the portals can project. At this point, the player’s only unused mechanic is the secondary portal. Still, despite revealing these few mechanics in the opening test chambers, the player is never subject to any more, only ever new questions for these same rules.

I'm unsure if I can convey this brilliance in words alone and I'd highly recommend revisiting Portal with it's Developer Commentary, which elaborates this further. What I can say is that this realisation of 'Iterative Design', is going to be my personal incentive for future projects. And I will use the learning mechanisms of Portal as a blue print for how to educate the player.