Whenever you play a game, you are constantly being fed information about the game’s state through your senses. These are most commonly conveyed through things like character animations, UI elements, particle effects, and so on. As a designer, it’s extremely valuable to know exactly what ways information can be conveyed to the player at any given time. Why? Because of mental bandwidth.
When I say “mental bandwidth”, I mean this - people can only process so much information being picked up by a particular sense at once. When humans look at things, we can only focus our attention on so many things before we become overwhelmed. This is normal; creatures have evolved this trait over thousands of years to prioritize important things like survival. This applies to all of your senses, not just sight - it’s why you can tune out ambient noises in order to listen to specific conversation, or why you don’t feel the clothes against your skin but you do feel the things your fingers are touching. The average human brain can only process so much information from a single sense at once - hence the term ‘bandwidth’. We humans have an upper limit on how much we can process. So what does this have to do with game design?
As a game designer, you’ve got to convey a constant flow of game information to the player, and you want to avoid overwhelming them with it. A classic example of this would be sitting down in a flight simulator and seeing fifteen hundred different buttons, dials, and meters. That much visual information will completely overwhelm a new player and make them drop the game. This is a problem often caused by overly cluttered UI, because it requires the player to focus their eyes on each one (if only for a moment) to get that information into their brains.
Avoid hitting that mental bandwidth limit by using a different sense to convey that information. The player might not need a UI element to look at, for example. Here are a few examples of games utilizing different channels to disperse the amount of information they convey to the player at once.
Call of Duty uses your peripheral vision to convey when you’ve taken damage. You don’t need a life meter, because the blur effect and reddening of the screen tells you everything you need to know. We use our peripheral vision to spot changes or movements even if we don’t necessarily focus our eyes directly on them. This enables players to keep their visual focus on their targets while still conveying information about health and enemy attackers to them.
Even small things like controller rumble can be used to convey worthwhile information. In Persona 4, Atlus added a fishing minigame. The controller rumble during the fishing game actually conveyed the kind of fish you could potentially catch, which made it a means of selecting the kind of fish you wanted to try for. This allowed you to make the best use of your fishing bait, and removed some of the randomness from the minigame.
Overwatch does a great job of offloading important information to sound and audio in order to convey information. Blizzard added a sound priority system to the game in order to make sure that you hear things that are most important to you depending on the context. If you are in the middle of a battle, for example, it reduces the priority of hearing things like footsteps - especially of those characters you cannot see. Instead, the engine prioritizes the barks of the characters calling out their special moves (like their ultimates) in order to give you as much information as you can get. Furthermore, each of the barks is filtered on a contextual basis. For example, when Pharah uses her Barrage ultimate, she shouts “Justice rains from above!” if you’re playing as her or her enemy, but “Rocket barrage incoming!” to her teammates.
In addition to all of this, a designer can emphasize important elements by expanding the number of channels that the information is being conveyed on. Instead of trying to avoid sensory overload, you actually emphasize a specific event by telling the player that it’s important through as many different mental channels as you can. If you remember the post-nuclear explosion scene in Call of Duty 4: Modern Warfare, you can see many of these elements working together in order to feed into the single experience that the designers were trying to convey. The player’s movement speed has been reduced to the prone crawl. The audio is a mix of a heartbeat, radio chatter, and winds. The player’s vision becomes blurry. It’s a powerful effect, because every channel available to you is reinforcing the horror of the scene being depicted.
A good designer is cognizant of the mental channels available to convey information to the player. You can use this as a tool to reduce the amount of information pushed through a channel like direct visual focus, or you can use it in tandem with other channels to convey a much stronger effect. If you want to be a game designer, you should keep this in your pocket as a tool to use when the time is right. Using it properly can emphasize key elements of your game, decrease sensory overload, and even differentiate your game from competitors if you convey information in an interesting or novel manner.