One of the most basic tenants of Game Design is Game Flow: the near continuous pace of events that happen in your game and how they relate to each. Flow is used to hopefully induce in players a trance like state in which immersion levels are at their highest, causing player to feel so ingrained in your game that the real world becomes secondary. Of course, the makeup and goal of each game will itself dictate that different games demand different flow. A Horror game will have a slower pace of active events than a Racing game would because of the difference of theme. Sometimes it is a mechanical limitation that varies the flow of each game, such as the difference in control design when comparing genres like Sandbox games and On-Rail Shooters. A good comparison for Game Flow is to think of it as if the player is a going through a piece of sheet music at its intended pace. Each note is some action the game makes towards the player, such as an enemy appearing or narrator voice kicking in. That sequence of events at the pace they are happening is the game’s flow.
One of the best game genres for folks new to Game Design to visually see and understand a game’s flow is Shoot’Em’Up (or Shmup) Games. The reason for this is because in Shmup games, the player’s point of view is locked as the game auto proceeds with only three specific events: enemies that fly around (and at times towards) the player that the player should shoot at or avoid, occasionally shooting specific patterns of projectiles that the player must dodge, while bonus items occasionally appear that the player must collect. Players are purely responsive in these games and can only react to whatever the game throws at them in the order they appear, meaning the flow of the game is allowed to continue un-interrupted. Using these 3 events, the games can provoke the player to take any number of actions at any given tension level.
If you’ve ever played any vertical scrolling Shmup game, you’ll notice that it is a very common pattern to start off the game with one small wave of enemies coming in from the upper left followed shortly by the a similar wave coming in from the upper right (or vice versa). By doing this, the game attempts to persuade players to move to one side of the screen shooting upwards before then pulling their attention to the other side of the screen and having them move over there and continue shooting. Musically speaking, the game is doing two similar notes from two different directions and holding them equally amounts of time. Each of these notes of a small enemy wave, which is itself a low level threat but still demanding of player attention that yields satisfying feedback in their destruction at the hands of the player. The game starts the wave, holds it as it releases anywhere between 3 to 5 enemy fighters, stops. Player deals with them. Then the game issues another wave from the right, distinguishing that this next wave is separate from the last one by its new location which demands the player to move again. Two very simple actions that help set the pace of the game demanding the player’s attention before giving them a break to rest and breathe, however brief.
From there, the game still has plenty of options of events to throw at the player, but ensuring they are properly paced from each other is important. Sometimes you use a high tension event such as a long laser projectile that the player must constantly dodge away from before giving the player a 3 second break to relax or shoot an enemy before releasing another. Other times you simple bombard the left side of the screen to have the player remain stationary shooting on the right before then bombarding the previously safe side and forcing the player to move. Whatever occurs next though, the flow is the game is visually noticeable to both players and observers alike regarding just what type of attention the game is demanding of the player and in what intervals. Again, imagine each of these actions as a music note, with the pitch of the note being in connection to just how stressful or demanding it is of the player’s attention. Watch as game’s build to a crescendo before cutting or resuming a normal pace.
Of course, not all games have the luxury of that Shump games have when it comes to disallowing player interference with the game’s flow. Most games rely understandably so on the player first taking action in a relative calm state while the game then reacts to their movements. Side scrolling platformers tend to have their stages built similar to sheet music, with the player running at the standard expected pace of the game’s flow as they then encounters enemies and platforming puzzles set before them. Sandbox games try and guarantee that as players make basic movements through the city or wilderness that they are likely at certain intervals to encounter some dynamic event or receive information about a mission nearby. Fighting games rely on the mechanics they’ve given each character and how they interact and resolve with each other in determining how fast/slow the pace of fighting gets in their game.
Still, regardless of how they do it, all games perform this flow in order to get players to “zone out” completely from reality as they become fully immersed into the game. Once players are in this sort of trance, the true escapist nature of games becomes apparent as players find themselves completely engrossed in games. In these states, players cannot even think of themselves as simply controlling a virtual avatar but instead the controls of the game become extensions of their very thought process. The better the flow of a game, the easier it will be for a game to achieve this trance.
As for how far players can get addicted to that trance and the moral question designers have regarding when to purposely break these moments, those are all subjects for another time. Still, I hope this basic lesson in flow and trance was helpful to anyone just starting to understand Game Design and provides some food for thought as you design your next game.