Tension and release form a cornerstone in all branches of art. Whether we're making movies, buildings, stories, songs, or games, these concepts are two sides of the same important coin. Creators use them to engage us in both obvious and subliminal ways, absorbing us emotionally. Without tension and release, artists from Shakespeare to Hendrix would have been at a complete loss.

We've all been exposed to theories on tension and release. We learn about the use of conflict in dramatic structure at an early age. Musicians study tension and release in their first scales and chord progressions, although the theory is less observable than in storytelling. And even as children we appreciate tension and release in architecture before we can consciously describe them. Indeed, all great creative works depend on good use of tension and release, and video games are no exception.

While "tension and release" sounds like the subject of a Farrelly Brothers movie, these concepts are absolutely valuable to the design process. Unfortunately, I rarely hear developers talk about this aspect of their projects. It's unfortunate because tension manifests itself as a unique and powerful force in games.

Such a fundamental theory deserves more discussion in our industry, so I'd like to take a look at games from the perspective of tension and release. The concept unifies approaches to all art forms, so I'll try to distill this aspect of game development in particular.

As a disclaimer, let me say that the use of these tools in games and other media is not groundbreaking in any way -- on the contrary, conflict is always at the forefront of developers' minds. My goal is only to draw some lines between games and other art forms, citing some examples and ultimately showing that this young industry knows what it's doing.

Also, I want to focus on usage specific to games. While most titles include elements of storytelling, music, cinematics, and architecture, these subsets don't reflect the interactive aspect of games. Since this portion truly sets games apart from other media, I'll try to concentrate on the gameplay implications of tension and release. There are aspects of game design that don't rely entirely on tension (character creation and upgrades, for example), but I'll focus on the areas I think are relevant.

Lots in Common

No matter what arena you choose, tension is the state of mental or emotional strain. Conflict, stress, pressure, and anxiety are all ways to describe this very animal emotion. It usually has a negative connotation -- people generally try to keep their tension at a minimum.

Paradoxically, tension is a must-have in any artistic experience. People absolutely need it in order to enjoy a movie, book, or game. We all know that icky feeling at the end of a movie's second act, when everything is going great but we know something bad has to happen. Deep down we need that horrible thing to happen; we need our character to overcome it. It's the same with the rest of art -- tension is crucial.

The need for narrative conflict is common to younger and older audiences, too. It doesn't matter what form these struggles take -- just look at the different tension in shows from Thomas the Tank Engine to Lost and even Murder, She Wrote. Granted, these are clichéd examples that don't fully represent their audiences, but I think they demonstrate three completely different ways for building and releasing tension.

Thomas and his friends deal with emotional conflicts; the characters of Lost fight against themselves and nature; Jessica Fletcher is constantly entangled in murder investigations. These series may have dissimilar premises, tones, and viewers, but each episode relies on masterful use of tension and release to build and overcome conflict.

Along the same lines, let's look at three different games. God of War III, Warcraft III, and Team Fortress 2 are each highly rated titles without too much in common. However, all three games masterfully build and release tension in distinct ways.

The God of War franchise is built on players defeating a series of enemy encounters, each delimited by a period of exploration. The result is a carefully planned roller coaster of tension and release -- players build tension through platforming and being attacked, finally releasing that tension by defeating a group of enemies.

Warcraft III builds tension slowly, with most matches culminating in a climactic struggle. As players create and upgrade more enemies, they raise the stakes toward this final battle of annihilation.

Team Fortress 2

Different still is Team Fortress 2, which maintains a continually high degree of tension throughout each match. As players kill or are killed in specific skirmishes, the downtime during respawn and resupply provide the release from this tension, resulting in a more flexible experience of tension.

Here we see the real blessing of tension and release in video games. Where the audience can only watch the conflict in other art forms, players have the chance to influence the game's tension and release it through its mechanics. Interactive media is more than just choices; obviously choices need to result in tangible consequences. Tension and its release are two of these consequences, and they triumph in games because people respond to them emotionally. A game's goals propel the player through tension; the game's mechanics are the source of its release.

Games in Particular

Games are great at creating tension. From the abstract sport that is Pong to the perils of Pitfall!, they can make us feel on edge. They also give us the tools to overcome our tension, whether we score a goal or swing across the treacherous quicksand. And developers have only gotten better over the years. Modern games are finely-tuned tension machines, built to work us up and calm us down over the course of a few hours. This is a key to making players excited and engaged in our games.

In fact, I believe one of the most crucial aspects to development is managing player tension. The ups and downs of the player experience are sometimes referred to as "story beats," but player tension has to be managed well beyond the narrative level. Between the overall story structure and the moment-to-moment gameplay lays a spectrum of opportunity for conflict.

The team behind Halo 3 is known for focusing on "30 seconds of fun" -- the ideal quantum of tension for their particular brand of running and gunning. Like God of War III, Halo 3 is roughly broken into discreet encounters designed to take around 30 seconds to complete.

Players appreciate the tension during these intense battles, which they shortly overcome by killing enemies and moving on. This cycle of tension and release is repeated hundreds of times throughout the game. Different titles succeed with different intervals; an extreme example like Tetris will repeat the sequence every three seconds.

Tension doesn't have to rise and fall so quickly. In the hugely popular Shadow of the Colossus, players can defeat only sixteen enemies. Most of the game world is completely safe, with real tension only occurring at certain points.

Of course, these colossi are massive threats by themselves and take lots of work to overcome. When fighting a colossus, the game uses every trick in the book to raise the player's tension: the sheer size of the enemy, the need to climb it to towering heights while it moves, the search for weak points in a hazardous situation, dramatic music, and obviously the fear of death.

Meanwhile, the player has the necessary means to overcome the tension -- he just has to do it. Victory in SotC is particularly satisfying, but not just because of its difficulty. It's not the most difficult game to beat, but it doesn't have to be. The heightened feeling of triumph is an emotional response following a period of particularly heightened tension.

Shadow of the Colossus

Since players can influence the amount of tension in the game world, it's important to design our games with this dynamism in mind. Grand Theft Auto IV does this beautifully with its dynamic star-rated police response. The developers are able to ramp the tension according to player actions, deepening the sense of open world mayhem. Players can then get the elevated emotional response they're looking for when they take that rocket launcher to a water tower.

Players can even negatively affect tension levels by doing something "bad," like killing an innocent NPC. We get satisfaction from killing an enemy partly because he represents a threat (tension) that we need to neutralize (release). Killing a nun in Red Dead Redemption may be amusing, but it's just not as satisfying. Unless we have some previous conflict with nuns, we're not releasing any tension -- just creating some irresolvable tension.

Tension can and should happen on different scales. As in film, many games involve an overarching narrative conflict at a high level. We know from the onset that Kratos has to kill Ares. Games are often broken into acts and missions in which tension builds and resolves on a smaller scale. At a lower level, the Devil May Cry series uses discreet enemy encounters to build and release tension. Gears of War II even creates tension when players reload; the timing mini-game gives them something else to worry about during firefights.

We're all familiar with timing challenges like this; developers frequently use them for their ability to create stress. In addition to their other conflict, some titles like Team Fortress 2 warn players when there are ten seconds left. In the case of TF2 the warning almost never makes a difference about who wins, but this extra tension in the final moments makes it more exhilarating. This tension even increases player riskiness, which affects everyone's tactics.

Though it was probably originally implemented due to the genre's arcade roots, time running down in fighting games like Street Fighter II also creates anticipation that gets us all keyed up. Moments of high tension are remembered better, so they're a great way to hook players emotionally.

Tools for Tension

Music and games are alike in their fundamental need for tension (check out this article or this article for a great overview). Just as our eyes can sense conflict, our ears too can detect tension and release in sound. This conflict usually comes from skillful use of tonic and dominant tones, which people perceive as either discordant (building tension) or consonant (releasing tension). A musician can create anxiety just by playing certain chords, resolving it by playing others. We all know the harsh sound of a dominant seventh chord in silent movies, typically used when villains appear.

Grieg's In the Hall of the Mountain King is a short masterpiece of building tension, starting slow and quiet. The song grows progressively louder and faster, gaining more instruments and drama until the final musical explosion that resolves the tension. The pure building conflict of this piece makes for an amazing emotional ride.

Pacing is directly related to tension and release. In an effort to keep players interested, it's important for us to distribute a game's tension over time. At a fundamental level, both musical pieces and games are patterns that snare us emotionally with their tension.

As creators, it's easy to overdo it and even easier to skimp out. People are bored by too little tension -- too much of it makes them give up. Great songs will spoon out just enough dissonance and resolve it before listeners lose interest.

Likewise, a good game will pace tension, usually in the form of action, conflict, and difficult decisions. Players are able to resolve it at an appropriate rate, keeping them interested.

Like pacing, difficulty is all about tension and release. Because players have different abilities and personalities, they may want to raise or lower the levels of tension they experience. Difficulty levels provide a way to tailor this. They don't exist just to make the game last longer or even to make it fair.

In fact, in Daniel Boutros' Game Developer article on designing difficulty, the author touches on the "Illusion of Fairness." It's much more important for the player to feel appropriately engaged than fairly matched. Too much difficulty leads to unresolved tension and too little difficulty results in too much resolution, either of which will kill any experience. At the beginning of a game, the levels of tension are necessarily smaller than later on. Enemies are introduced in smaller groups, since the unknown creates its own tension.

Like the rising tension of dramatic structure, risks and their rewards should grow over time and experience. We can think of risk and reward as incentivized tension and release. As developers, we spend lots of time balancing risk with reward.

While it sounds obvious, it's crucial to maintain tension in the risks and release in the rewards. It's all too easy to create a risk that doesn't generate player anxiety, like an unforeseeable trap or death falls that don't look hazardous. Likewise, rewards that don't resolve the conflict of risks are not satisfying because they can feel gifted and not earned. At the moment of reward, we immediately recall the threats leading up to it. A good dose of tension and release can only heighten player engagement.

Game mechanics themselves can be thought of as devices for tension and release. Genres are based on types of tension. Platformers are built on the tension humans feel when jumping and landing. The anticipation before a jump, the anxiety of free-fall, and the resolution of landing are microcosms of the tension and release sequence.

Like many other game mechanics, jumping finds most of its appeal just from the tension it garners. After all, there's nothing fun about jumping over flat, non-threatening ground. But give players a canyon to leap over, and the same jumping mechanic will suddenly include the magical combination of stress and relief.

Racing games use speed in the same way -- no matter how fast you're going, it might as well be a Sunday drive without the pressure of other competitors. Puzzle games create a cognitive tension, and players feel rushes of triumph when it is released. Survival horror games wallow in it; players can overcome it in small doses, but they find fun in an ever-present cloud of unresolved tension.

Setups and payoffs are powerful tools in many areas of entertainment. They work by revealing information, changing topics, and then returning to said topic to push the story forward. Film, in particular, makes great use of audience memory to capitalize on the human need to connect the dots. If we understand the setup for what it is, we experience tension as we await the payoff. If the payoff hits us unaware, we enjoy the trick the artists have played on us.

The antlions in Half-Life 2 illustrate a flawless use of this concept in the arena of games. Players struggle against these foes for a large portion of the game, learning to fear and respect them. This setup raises tension, which is resolved when players finally gain the ability to control the antlions and use them against enemies. This payoff is a new mechanic and an emotional release, as players simultaneously become more powerful and turn their previous tension against the bad guys.

Changes and tension can happen in other ways as well. In Oblivion, players begin in a dank prison. They learn the game's basics as they fight through a series narrow corridors and gloomy crypts. But when they complete this introduction, players suddenly emerge from an oppressive underworld to a vast, colorful landscape.

It's also a release from the narrative itself, because up until this point they have been obeying instructions from NPCs. The game suddenly offers players complete freedom. This is a particularly memorable moment because it's a period of total tension release. Merely by resolving tension in the game's tone or independence, we can manipulate players' emotional hooks.

In a very different way, Call of Duty 4 completely changes the campaign's tension with its "Death From Above" section. In this mission, players rain down cannon fire on enemies from a cruising AC-130 gunship, observing the battlefield through a night vision lens. There are no immediate threats to players during this mission; instead, they must protect friendly soldiers and civilians on the ground.

This almost surreal detachment is a marked departure from previous levels, which are full of constant threats and twitchier gameplay. Like many other titles, it lets us change gears and wreak havoc while still keeping us engaged. One of the title's best-remembered sequences, this mission succeeds partly because of its contrast in tension.

Environmental Tension

Level design itself is a huge source of tension. Obviously the layout of hazards, enemies, puzzles, and power-ups are key to a good level. Toward this end, game development can find parallels with architecture. In Grant Hildebrand's Origins of Architectural Pleasure, the author argues that enticement and peril are two of the most important reactions that people demand from their environments. This conclusion is interesting because these emotions are different facets of tension.

The feeling of enticement is generated by buildings that promise new wonders just around the next corner. Examples include winding hallways, building exteriors that suggest exciting interiors, and transitions from dark to light.

People naturally wander through these spaces out of curiosity, a powerful form of tension. Architects and level designers use enticement to promote flow through a space. When players descend that final flight of stairs to the boss' lair, the level's basic architecture gives them a sense of dread. While exploring Crackdown's twisting streets, the level layout urges players just around the next corner. These pervasive forms of tension are valuable ways to keep us interested.

Crackdown

In a related way, people feel peril when they are threatened. But the "right" amount of peril is this fear combined with knowledge of safety. We enjoy scary places as long as we're secure, and many architects take advantage of this. Skyscrapers, bridges, and balconies are good examples of such areas. Level designers also use this appreciation of fear -- death falls, traps, and crumbling environments are tried and true tools.

Games already provide a sense of safety by the distinction between player and avatar. But aside from that, I believe a perfect amount of peril results from balancing player confidence with an unshakable feeling of anxiety. They should feel that their mastery of game mechanics is enough to get them through the situation, but still feel a sense of uncertain trepidation. It's our job to temper this environmental tension with the player's abilities to resolve it.

Conclusion

Games can be thought of as emotional manipulation machines, with developers responsible for a well-tuned experience. A lot of this comes from the ability to create and resolve tension, a concept common to all art. Games are unique in that players can build and release tension as they play.

It's a strength that we developers have mastered over the years, employing it in various ways to different projects. As our games grow more sophisticated, we will continue use it for more subtle and powerful emotional triggers. I think we should always be searching for more ways to add releasable tension to our projects.

It's obvious when titles lack a good balance between tension and release -- players feel it internally. We crave tension on every level, and we find joy in overcoming it. Exposing this delight to players is an indispensable way to hook them and make our games more successful.

I've focused solely on the role of tension in games, a pretty extreme perspective to be sure, but I believe it reveals a lot of practical knowledge. It's a classic and well-understood tool that we can use to heighten the player's experience at every level. Tension has roots in other disciplines, and we should remain open to learning from them.