Portal 2 is a 3D environmental puzzle game from Valve. The game has won several awards including the coveted Game developers conference awards for excellence in game design, writing and and audio. The gameplay revolves around solving navigational problems using portal guns and other devices available in the scenario. The improvisational use of the multi-functional portal guns is the core mechanic of the game. The interactions between portals and elements like light-bridge, cubes, lasers and gels allow players to generate innovative solutions to overcome well crafted puzzles.
Portal 2 has several well designed elements, but the level design stands apart in a class of its own. Starting from the controlled test chambers in the earlier levels to the extravagantly open spaces in the later scenarios, Portal 2 levels manage to pose challenging levels without overwhelming the players. The introduction of elements and abilities is managed through well designed puzzles, which manage to educate and challenge the players simultaneously. This allows portal to effortlessly train players without any explicit instructions. Portal’s approach to level design is a great example of facilitating transfer of learning in a playful environment. In the following sections, i break down multiple aspects and approaches in the level design of portal, which follow learning design principles for facilitating transfer of knowledge. Although the game also includes a well designed cooperative mode, i only discuss the level design of the single player campaign in this article.
Test chambers as controlled learning environments
A controlled learning environment plays a key role in efficient learning. The term ‘control’ refers to the intentional simplification of complex learning concepts. Consequently, controlling a learning environment refers to the process of identifying and extracting core concepts of a topic and designing a curricula around them. The challenging aspect of this process is not limited to including important parts, but also involves excluding irrelevant information.
As an analogy, imagine the body of knowledge of a topic as an iceberg. This body of knowledge is so vast that it is impossible to understand it all at once, especially for novice learners. Moreover, novice learners, who are still at the surface level cannot comprehend the knowledge hidden inside the depths of the water. Trying to explain the submerged part of the iceberg will only confuse them further. A controlled learning environment excludes ‘submerged’ information and introduces ‘surface level’ concepts before delving deep. It directs learners towards positive inclinations, which guide the interpretation of additional knowledge. It creates a simplified conceptual model, while ignoring the depths of knowledge beneath it. A common example of this is the falsification of previous knowledge as learners advance towards higher education. Concepts and facts learned in lower grade levels are constantly falsified and replaced with newer conflicting information. This is not a mere mistake, rather it is an intentional effort at simplifying concepts to make it digestible for novice learners. In other words, it is a real life example of a controlled learning environments.
Portal 2 implements controlled learning environments in the form of test chambers. The campaign begins in aperture relaxation chambers and introduces players to basic controls of the game. After the first level, players go through a series of test chambers. All test chambers have a clearly marked entry and exit and pose a simple goal for the player: to escape the chamber. This provides players with a clear sense of direction and a well defined goal. As a result, players are able to direct all their cognitive resources on problem-solving. This design decision allows players to quickly learn new concepts and apply them immediately without any major consequences. The deliberate inclusion of a small number of elements and the intentional exclusion of the full inventory of objects make the test chambers an efficient learning environment.
The test chambers are grouped together into chapters, with each chapter containing about 7-8 chambers. Each chapter follows a design pattern conducive to transfer of learning. There are several clever design decisions that ensure efficient learning while also providing engaging gameplay. Firstly, the first few test chambers in each chapter introduce the player to a new element. These chambers generate an ideal situation to intuitively inform the player about the utility of a new item. For example, ‘Test chamber 1’ introduces the player about navigating through portals. To accomplish this learning goal the test chamber utilizes pre-deployed portals, which can be activated with buttons. Interestingly enough, button triggered portals are hardly utilized in the game after this chamber. However, using them in the first test chamber helps generate an ideal situation to teach the concept of portal navigation without the additional effort of deciding where to place the portal using portal guns. The video walkthrough shared below demonstrates this design.
Secondly, each chapter references previously introduced elements and let’s player explore the interactions between all elements. This provides a platform for deliberate practice and repetition, which enhance retention and understanding of learned concepts. For example, Test chamber 1 in Chapter 2 requires players to utilize the portal gun mechanic in combination with the laser activation tool. This scenario introduce s lasers while enhancing the understanding of portal mechanics through repetition.
Thirdly, test chambers implement the worked example principle described in Cognitive Load Theory. The principle states that cognitive load can be considerably reduced and learning can be enhanced, when learners are shown a worked out example of the type of problem they are trying to solve. Portal 2 manages to do this time and again by introducing semi- functional elements. For example, the test chamber shown above cinematically demonstrates how lasers work. The solution then, is to manipulate a functioning laser, rather than activating it. Moreover, the deliberate exclusion of other elements in the chamber helps guide the players attention to the learning content.
To summarize, Portal 2 test chambers help players learn new concepts through controlled situations, remember learned content through repetition and enhance their understanding by utilizing their knowledge in various situations.
‘The Escape’ towards transfer of learning
After going through a series of test chambers in the first four chapters, the level design of Portal 2 takes a drastic turn. The familiarity of a marked entry, exit and goal is stripped away and the noise of a ‘real’ environment comes into play. The fifth chapter called ‘The Escape’ sets the precedence of pushing players to apply their knowledge in unfamiliar scenarios. This idea, commonly known as ‘transfer of learning’, refers to application of knowledge in situations unlike the ones where it was learned. It is an important factor in assessing the efficiency of learnin, as the goal of educating is to prepare learners to apply their knowledge in the real world.
Through it’s level design, Portal 2 pushes players to demonstrate what is commonly known as ‘near transfer’. Near transfer is the application of prior knowledge in situations that are different yet somewhat similar to the learning context. It requires an understanding of the content and adequate experience of practicing that knowledge in a variety of situations. In the case of Portal 2, the test chambers ensure that the players comply to these requirements. As a result, the following chapters are set on the right platform to challenge players to transfer their skills. They challenge players to navigate for necessary resources and ideate unique solutions using familiar tools.
The level design for these chapters is noteworthy as the challenges posed to the players are conducive to abstraction of knowledge. They direct players to extract general rules and principles from their existing knowledge of the game. For example the portal guns used for solving puzzle are now used for transportation, leading to the realization of the principle of portal travel. Similarly, the principle of conservation of momentum is taught by posing the players with challenges that are not as straightforward as before and require an understanding of the concept. The design of these levels is significantly different than those of the test chambers yet equally well implemented. This is demonstrated by the subtle visual hints and environmental guidance provided by the levels. For example, Puzzles that require projectile movement contain diagonally facing portals, which imply a portal jump as a part of the solution. Similarly, arrows and signs guide the navigation of the players without spoon-feeding the answers.
These factors make Portal 2’s level design an important artifact for educators and learning scientists. It exhibits an efficient implementation of learning principles in a playful environment. The ease with which the game manages to train its players and impart a substantial amount of knowledge is noteworthy and makes it an inspirational piece in the domain of learning design.