Let’s say you find yourself in a small, quiet room. The only point of interest in this room is the southern wall, upon which there are three light switches, all in the off position. One of these three switches operates a table lamp in a room located on the other side of the building. You can leave the switch room to go examine the lamp, but if you do, the door to the switch room closes forever. You can’t see, hear, or otherwise perceive the state of the lamp from the switch room. So, using nothing but these three light switches and your one trip out of the room, tell me which switch controls the lamp.

There’s enough information in the above paragraph to solve the problem, I promise (I’ll reveal the solution at the end of this post). Solving the problem requires you to think about it in a new, unusual way. If you want to win, you have to think outside the box. Take an intuitive leap. Think different. Shift the paradigm. Do some lateral thinking. You can describe this type of problem with whichever cliché you like best, but a psychologist would call it an “insight problem”.

An insight problem is fundamentally different from, say, an algebraic equation, a Sudoku, or a Rubik’s Cube. No matter how tricky the math looks, how many numbers are missing from the Sudoku grid, or how long the Cube has been sitting in a disused desk drawer in your attic, you can solve these puzzles. Given a complete understanding of the rules and enough time, a solution is inevitable. Insight problems, on the other hand, carry no such guarantee. If you can’t think creatively, you can’t solve the problem, and perhaps you never will.

The requirements of insight problems are different from those of non-insight problems. It should come as no surprise to you, then, that the feeling of solving an insight problem is different as well. This was studied back in the late ’80s. Researchers gave subjects sets of problems to complete, and asked them to rate how close they felt they were to the solution every fifteen seconds. Ratings for non-insight problems followed a predictable pattern; as subjects got closer to the solutions, they felt like they were getting closer. But the insight problems were different. As subjects chewed on the insight problems, their ratings never budged, until the moment the solution came to them. The subjects felt as if they were treading water, turning the problem over and over again in their minds, and then suddenly—bang, boom, eureka!—something clicked, and all at once the solution was obvious.

I can’t help but think of the recently released Portal 2 and its predecessor, Portal, as the world’s most successful insight experiments. Before I get into why, let’s take care of the preliminaries. Portal is a perfect video game (and Portal 2 is a near-perfect successor). I don’t say that often, but it’s true. As a game, as a story, and as an interactive experience, Portal lacks for nothing. It is thrilling every step of the way and sticks around for exactly the right amount of time. If you haven’t played it yet, you should buy it right now. It costs a measly ten dollars.

Portal is a puzzle game. The goal of each puzzle is to get from the entrance of each testing chamber to its exit. Your only tool is the Aperture Science Handheld Portal Device, a gun-like object that does one thing: creates a wormhole linking any two flat surfaces. If you’ve never played Portal, this video from an earlier version of the game is worth a thousand words.

With the portal gun in your hand, everything you’ve ever learned about moving through your environment, about the laws of physics, is suddenly open to negotiation. The portal gun breaks your assumptions about how the world works and gives you abilities you can only discover through experimentation. The point is this: playing Portal requires insight.

This stands in stark contrast to just about every other video game ever made.Games like Halo and Call of Duty may be dressed in fancy clothes, but really, all you have to do is murder your way to victory. In _Mass Effect 2, _an excellent game set apart by its top-notch writing and expansive atmosphere, you murder your way to the next dialogue tree. I’m not saying that you don’t need skill to play these games, or that you can’t play them creatively, but they require the sort of skill and creativity you’d employ to solve a particularly hard math problem, with guns.

There are other types of games, of course, games like Sam & Max or Curse of Monkey Island, that require a fair bit of creative thinking, but the creativity here is oddly constrained. It’s all about figuring out which quirky item from your quirky inventory you need to use on some oddly specific (quirky) part of the quirky world to progress to the next quirky set piece. So whether you’re playing Bioshock or Day of the Tentacle, the rules are clear, the win condition is readily apparent, and victory is, in a sense, inevitable.

Portal is an entirely different beast. There are no health meters, no command menus, no inventory screens, no neatly written mission objectives, and no hint system. You have one weapon, and it does exactly one thing; the game is all in how you use it. In most testing chambers you can see your goal from the very start. The only question is how you’re going to get there, and the only way to answer that question is to explore the chamber. So, you start looking around. You move through the chamber, perhaps taking note of which surfaces are portal-compatible and which aren’t. You might notice that there’s a button that needs pressing on the floor over here, and over yonder, on the other side of a bottomless pit, a big weighted box that could be placed on top of it. But how do you unite the box and the button? With your trusty portal gun, obviously.

Obviously. All you have to do is use the portal gun to…

Obviously…no, that won’t work. Maybe if you put one portal on this wall, and the other on the floor…

Obviously? No, clearly not. Alright, let’s see how things look when you portal yourself over to the box and…nope.

Obviously this is impossible. Who the hell designed this thing? This test chamber is unsolvable. You’d need an extra box, or another way to press the big button. But to do that you’d need to figure out some way to simultaneously get both of the…



And just like that—bang, boom, eureka!—the solution becomes obvious, all in a flash of insight.

The only thing harder than solving an insight problem is creating one for someone else to solve. You have to provide just enough information to make the problem solvable, but not so much that the problem becomes too easy or straightforward. Insight problems are very experiential. As I said earlier, solving them feels different from normal problem-solving. Unbelievably, the fine folks at Valve Software have created a game that generates the insight experience, that undefinable eureka feeling, over and over again (that Valve accomplishes this by meticulously testing and quantifying player behavior is another feat in and of itself). Forget Portal’s pitch perfect dark humor, its strangely immersive storytelling, or the wonderful look of the game. Portal, as a game, is about capturing that moment of insight. The reward the player receives for solving each test chamber is transient, unique, powerful, and entirely internal. No other game has ever offered something this pure to the player. No other game triggers this sort of feeling in the player’s brain. This, I believe, is what has made the Portal series such a wild success.

In closing, let’s return to our hypothetical light switch room. Using just these three switches and a single trip outside to check on the lamp, how can you tell which switch is the right one? Let’s label the switches A, B, and C for convenience. Turn on switches A and B. Now wait fifteen minutes or so. Turn off switch B. Congratulations, you’ve just solved the problem. Exit the switch room and go examine the lamp. If the light is still on, then obviously switch A is the right one. If the light is off, feel the bulb. Is it hot? If so, then switch B, which powered the lamp for fifteen minutes, is the right one. Finally, if the bulb is cold that means its switch wasn’t turned on at all, so switch C is the correct answer.