Staples of Game Design, Part II: The Key

This article was posted originally on the > Inline Comment blog.

Another staple of traditional game design is The Key. In my life as a gamer, I have found thousands of keys for doors, keys for treasure chests, keys for locks and even keys for the game itself. Here are my opinions about keys in game design, what they are, where they make sense, when not to use them and some food for thought.

Much like with The Crate, the concept of The Key is also taken from the world outside of games. It needs no explanation to the player because we all know how it works; essentially the concept of The Key is a two-component construct, each element is unique and requires the other. Just one alone won’t get you very far. A locked door without a possibility to open it is a wall, a key without a matching lock is litter. Still, I continue referring to this trope here as The Key because it’s short and it fits better in your inventory.

The Concept in Games.

Whether players need an actual key, a key-card, a code, a lock-pick, twenty-thousand-five-hundred-and-thirty-six XP, 40 gil or a moustache out of cat hair, the result is the same. Possessing the required qualification at a certain point in the game lets players advance or experience something new (an area, an item, a story) which was inaccessible and/or hidden to them before.

I know, that is quite a wide definition of The Key, but I will narrow it down where necessary.

The Key Element.

As I understand it, the main purpose of The Key is to slow down the progression of the player. If they end up in front of a locked something, it hinders them on their way through the content of the game. “Sorry pal, gotta find the right key!”.

For designers, this seems favorable because it means for one thing that the player won’t be able to burn through all that content we worked for many months so hard to create. Further, when encountering a lock the player will act in a quite predictable way: They will examine their surroundings more closely (i.e. they are forced to appreciate all the content you put up so far for them). If they don’t find anything that helps them, they will begin to backtrack to get that stupid key, cursing under their breath because that sucks. Looking for my car keys sucks too.

Variations of The Key.

Any Key.

Interesting to note is that some games misinterpret the concept of The Key, they deviate from it in ways that don’t seem logical to the player expecting it to work like they are familiar with in their reality.

Take games that let you collect keys like a resource. Keys are not sorted after which lock they open; rather they are treated as a batch of instances, e.g. “Keys: 42”. Any lock takes any key but unlocking it consumes one key. Because the lock just eats it.

In games like The Binding of Isaac this is not really a big deal, but in RPGs, for example, or other games that pride themselves with depicting the “real world”, this can be annoying up to a point of immersion-breaking. If that’s how your game treats keys, think of a different metaphor. So opening that lock requires a certain amount of consumable in-game resource, e.g. stamina, explosives, money, etc.

The Lever.

We know this from the first couple of Tomb Raider games. You pull a lever in one room and somewhere a door opens. Their only difference to keys is that they are stationary, they can’t be picked up by the player. In Tomb Raider, many open doors are on a timer. To me, that’s a great element to justify a lever because its property of being immovable is considered in the mechanics.

The Button.

Buttons in games can be much more than act as a lock, but just a single one essentially unlocks new content for the player. Portal showed me that it’s a bit more than The Lever in that respect. It’s stationary as well, but it can also be operated as a pressure plate. While switching The Lever often is permanent, buttons have a tendency to reset, they can be pushed multiple times. To me, buttons are the prototype of player interaction, and I might write up a whole article just dealing with it because there’s more to it than you would think.

Designing around Keys.

While keys are neither good nor bad in and of themselves, their implementation can suffer from just lazily adopting this trope without considering your game’s needs. It all depends on your genre, mechanics and how much you want to frustrate your players (or not), of course. In any case being aware of the pros and cons of the different approaches always helps.

When your player is in the flow of your game, the last thing you want to do is break it. This leads to frustration. (A lot of F2P games do this on purpose to squeeze some money out of their players, but that’s a different story). So how can you have keys in your game then without frustrating the player?

The Key needs to be part of your core mechanic in some way and not just tacked on to artificially slow down players. One genre that has the Key mechanic at its core are adventure games: “Solve this puzzle here and now there’s a bunch of new content for you to discover!”. Any item or dialog option can act as a key to unlock new content. “Classic” adventure games are a series of intertwined locks you need to find the right key for, it’s just a different kind of key each time. If you don’t, there’s nothing new. Players of adventure games know this. Players of adventure games expect this. Done right, the hunt for keys is not frustrating, it’s intriguing.

Adventure game design is an art of its own (just read Ron Gilbert’s blog, it’s a treasure trove!) so you should embrace the fact that you are just cleverly littering the world with keys in a world of locks. The great The Room series on mobile demonstrates how fascinating this can be.

How about other genres/mechanics? As already mentioned, The Key doesn’t have to resemble one literally. Many RPGs award players XP for their actions. Get a certain amount of XP and your character levels up which allows them to use items/equipment/passages that were locked to them before.

Use the player character’s abilities as keys. That’s the Metroidvania way of doing things, which I find very rewarding in action adventure games if it weren’t for that pesky backtracking. (Personally, I don’t like backtracking very much, maybe I should write a whole article about this topic as well). You always notice the wall with the crack, the platform with the crate that’s too high for your jump, the passage you can’t get through yet. Once you’ve learned a new ability, walls suddenly transform into doors for you and unlock new content. To me, that’s fun.

As you can see from these examples, the act of acquiring The Key is the game itself, it is what’s fun for the players. The frustration sets in when the need to find the Key to a given Lock stops the players in their tracks from enjoying the gameplay. And that is what should be in your focus.

Food for thought.

When we were shooting a film back in 2012, we filmed on the location of an abandoned factory building for a few weeks. While we had a break, I explored the fascinating premises and in a warehouse beneath the leaking ceiling and among a pile of discarded, rotting folders I found a single key in the dust. It was relatively heavy and had a bleached out label on one end, impossible to read. I took it with me; I don’t know why. Probably because of all the games I played. The following days I explored some more, looked for doors and locks, but none would take the strange key. We wrapped and one year later the old factory was gone, and now there are clean new family homes. I still have the key. And I still wonder, what lock it would have opened and where the new passage would have led me to…

Some Keys in Gaming History.