Affordances in Level Design: how players interact with your level
Stormtroopers are closing in and I’m taking heavy fire. I quickly activate my personal shield and sprint back to relative safety. The forest moon of Endor has dense vegetation, which often makes it difficult to distinguish enemies from the surroundings. I find a cluster of bushes that ought to make me virtually invisible. I dive into my perceived save spot to regenerate health, but it isn’t long before blaster fire from halfway across the map takes me out.
“How did they know I was there…?” I wonder.
‘Forest moon of Endor’ map from ‘Star Wars Battlefront’ (2015), EA DICE
This was an experience I recently had playing EA DICE’S Star Wars Battlefront (2015). The answer is that the bushes don’t have collision set up to allow the player to move through them, and for the enemy’s ‘sight-line calculation’ it doesn’t act as a blocker.
Because it’s an opaque object that the player can’t see through, they expect to be able to hide behind/in it, like you would in the real world.
In game & level design we consider this expectation an affordance.
The inconsistency between the affordance and the actual interaction is called a false affordance. Those are often responsible for jarring and frustrating experiences in the video games you play.
Origin & meaning
The term “affordance” was first coined in 1966 by psychologist James J. Gibson, which he later refined into “Affordance is what the environment offers the individual”.
This term was later appropriated by the field of interaction design and describes the properties of an object and what a person can do with them.
There are many written works on the topic of affordances and many slightly different interpretations. Rather than writing in tedious length, let’s consider this an introduction to the topic, keep things simple and only view it through the lens of level design.
“Affordances of concrete draining pipe” - by Avadh Dwivedi
What we’re concerned with are perceived affordances. This is in which ways you expect to be able to interact with an object, based on observing it.
You think you can pick something up because it looks light? That’s an affordance.
You think something is going to bounce when dropped? That’s an affordance too!
Real World Examples
A mug can hold liquid, or small items.
It’s small enough to be picked up
Should be held by the handle
It can be thrown
It might shatter on impact (depending on the material)
Those are all perceived affordances.
Doors are a famous example of affordances that are poorly designed/communicated in everyday life.
Many of us have made the mistake to pull on a door, only to realize that it should’ve been pushed to open.
However, when designed right, this confusion could be eliminated altogether. Standardized visual language subconsciously tells you whether to push or pull.
Also generally accepted is: Horizontal handle = push, Vertical handle = pull
Affordance and signifiers in games
As a gamer, you’d know instantly that a red barrel explodes when damaged. Also cars and other vehicles will start to smoke and then explode when fired upon.
Even though objects don’t tend to behave like that in the real world, in games we’ve been conditioned to associate those behaviors.
Naughty Dog’s Uncharted series does a marvelous job at using affordances to intuitively guide the player. They often color code specific interactive elements or use other visual markers consistently.
In the image above, not only does the branch sticking out convey an affordance, there’s also a bit of rope already wrapped around it that signifies the player can attach their grappling hook to swing from it.
Throughout the game, all objects that can be grappled, will have bits of rope wrapped around them.
Those kind of specific indications that an object allows a certain interaction (read: have a certain affordance) are often referred to as signifiers.
Spinning fans & anti-affordances
Respawn Entertainment’s Jedi Fallen Order
Early on in Jedi: Fallen Order, you encounter rapidly spinning fans. Rather than the affordance that this space can be crossed, it has the corresponding anti-affordance: This passage can not be crossed and will hurt you.
Fallen Order then teaches you the signifier that objects with a blue outline can be interacted with, using your force abilities. Not only do they naturally stand out, glowing objects and outlines are often used in video games to signify that the player can interact with them in one way or another. Therefore you can almost bet on it that players will understand this, though sometimes it can still be a good idea to clarify.
Where do affordances come from?
I find most affordances are ingrained in us through 3 main avenues:
Real world experience: Fire is hot, snow is cold. Many of us have experienced this in one way or another.
Popular culture: A defibrillator will restart someone’s heart when it has stopped beating or even bring someone back from the brink of death.
Other video games: There’s a box of ammo lying around? You can pick that up, but not many similarly sized objects.
The defibrillator helps you revive fallen enemies in Battlefield 3
It seems that regardless the original source of perceived affordances, they all seem to have one thing in common: Consistent exposure to certain properties and behaviour of objects and your environment will make people expect the same behaviour in the future, regardless of it coming from reality or fiction.
After all, we humans love our pattern recognition.
Create your own affordances
As people form their own sense of affordances based on consistent exposure, it’s perfectly fine to craft your own specific affordances for your own game. In fact, many games do this!
For example, paint everything you can grab onto in your game a shade of yellow, and keep this consistent (the Uncharted series often does this).
Or use a specific, clearly visible logo on all items that can be picked up. After a couple of pickups, the player should have learned to look for this logo when in need for e.g. health & ammo.
The colour yellow, always handily painted on elements that can be grabbed in Uncharted 3
Keep in mind that while creating your own affordances is totally okay, it can get confusing when you use too many for the player to really remember or when they contradict an affordance from the real world or other games. So definitely do your research about which affordances your target audience might already have. Play recent games (especially games in the same genre as the one you’re building) and pay close attention to which real-world and popular culture connotations might exist about your environments.
Let’s quickly look at a couple of standard practices to keep in mind for your levels:
Can you fit between two spaces?
If it looks like the player character might be able to fit, players will try to squeeze through it and will be frustrated when this doesn’t work. Either space them further apart, move them closer together or place clear visual blockers in between.
In Star Wars Jedi: Fallen Order the player can often fit through narrow spaces. This isn’t too common in games though.
Is it high enough to jump or climb?
Pay attention to height differences in your level. Figure out the character jump height and classify your objects and ledges as jumpable or not jumpable. Avoid anything being close in height to that limit which you actually can’t jump upon. If it looks low enough to jump on as a player, it should be!
Can you jump this gap?
There’s hardly anything more frustrating than dying in a video game and feeling like it wasn’t your fault, but the games’. This tends to happen when there’s a gap just slightly too large for the player to jump. Make sure those jumps can always be made, or it should be plainly obvious that it’s too far.
Is this destructible?
Adhere to a clear visual language for anything that can be destroyed. Think of the cracks in rocks and walls in the legend of Zelda series. If those cracks were then used anywhere else, this would create a false affordance for the player. On the other hand, if some objects break while not having any visual indication but others don’t, players will now have to play the guessing game with every single object in your game.
Throughout the Legend of Zelda series, cracked walls indicate that they can be blown up to reveal hidden pathways.
When affordances are applied correctly in your level design, the player should hardly notice them. Of course they could open that door and jump over that gap in the floor! Of course they were clever enough to find out there was an easter egg hiding behind those damaged wall panels!
It’s when players continuously feel they should be able to do something but can’t, or when they keep missing what you thought were ‘obvious actions’ to progress, it’s the hallmark of poor affordance design.
So do your research, and if anything else, be consistent!
p.s. Rules are meant to be broken! False affordances can be created as part of puzzles or to add extra drama to a scene. But be very careful about where and when to apply inconsistencies.
EDIT (30/01/2020): I updated the article to more accurately distinguish between signifiers and affordances. Brief information about anti-affordances included.
Thanks to Tommy Norberg for the feedback!