Friday, April 20, 2018

approachable theory: Complexity in Game Design by Jacob Kellogg

The approachable theory logo, with the text "approachable theory" and an image of two six-sided dice with one pip showing, with a curved line below it to make a smile. The dice are black with cyan for the pip and yellow with black for the pip.
The approachable theory logo.
Today's approachable theory post is by Jacob Kellogg, creator of the new Journey Away rpg on Kickstarter, and is about complexity in game design! Find out more about Jacob after the post! Please read and enjoy. 

Jacob Kellogg, selfie portrait.
Complexity in game design can be a touchy subject. Sometimes a game is so complex that it feels more like work than play, or deters your loved ones from wanting to learn it. Other times, a game might be criticized for not being complex enough, with critics saying it’s been dumbed down. In some cases, you might even find both opinions regarding a single game.

If you’re designing a game (or even just like to ponder game design theory), this can leave you with some confusion about the role of complexity in design. How do you know if a game needs to be simpler or more complex? What does complexity offer to your design? What does it cost you? I hope to shed some light on this issue by defining complexity, detailing its relationship to the separate concept of depth, and sharing some other considerations about the role of complexity as well.

Before we get started, I’d like to give a shout out to the Extra Credits team, specifically this video, for the lessons I’ve learned on this and other topics thanks to their hard work. Check them out!

Now, we can’t really discuss complexity until we’re all on the same page about what it means. When I refer to complexity in terms of game design, I’m talking about all the details and rules that you have to learn (and all the gameplay actions that are required) to play the game. For example, if you have to roll a die to determine the success of an action, that’s more complex than if the action just succeeds by default, because you have to know the rule about how that die roll works. If a player might have a special quality that lets them re-roll the die if it comes up as a 1, that’s another rule to learn, and therefore another layer of complexity.

Now that we’re all on the same page about complexity, what does it contribute to our games? While there are a few answers to that question, the primary role of complexity is the creation of depth. What do I mean by depth? Depth in a game refers to the number of meaningfully different gameplay experiences that can be had. That is, if there are two different ways of doing things in a game, having those two paths actually FEEL different in play is depth. For example, if playing a speedster in a superhero game genuinely feels different than playing a hulking brute, that’s depth. If they feel the same in play, the depth is missing.

Picture of the Shadow Amps section of Shadowrun: Anarchy & note from Brie: here's a place where you have to look at the depth and complexity of different mechanic. Does this math result in greater depth in play? What do you think?
If we want to add depth to our games, we have to put some sort of rule or mechanism in place to differentiate the different play options, to make them feel different. Doing so is the definition of adding complexity. Therefore, the way we add depth to our games is by adding complexity.

But there’s a catch.

Not every unit of complexity produces the same amount of depth. Sometimes the addition of a small, simple rule will create a multitude of gameplay experiences, while other times the creation of a vast and detailed system will hardly be felt at all. Let’s look at another example.

Say we’re designing a traditional heroic fantasy RPG and deciding how different weapons compare to each other. If we want a two-handed greatsword and a little dagger to feel different in play (and we probably do), we need to add some complexity to define their differences. So, we decide that the greatsword deals a lot of damage and uses two hands, while the dagger deals piddly damage but only uses one hand and is easy to conceal under your clothes. Great! Now players can have genuinely different gameplay experiences (depth) with these two weapons, thanks to us adding a little bit of complexity.

Now let’s say we want to go a little further: we also want shields in our games, which can’t be used with a greatsword, but it feels weird for shield-users to be restricted to daggers for weapons, so we create a longsword to sit between the two. It deals less damage than the greatsword, but more than the dagger. The degree of depth between the longsword and either of the other weapons is smaller than the gap between the greatsword and the dagger, but it’s probably still noticeable, offering real depth to players.

But let’s go even further. I mean, there are more than three types of blades in the world, right? So we start adding bigger knives, smaller swords, axes, swords with different degrees of curve to the blade, and so forth. Conscious of creating depth, we make sure that each of these weapons is technically unique: most of them deal different amounts of damage from each other, and when we ran out of unique damage amounts, we started giving the redundant weapons special abilities, like slight bonuses to disarming your opponent or breaking their shields.

By the time we’re done, we have a two-page chart of weapons, but they’re so close to each other in their abilities that a character with one weapon could swap it out for a similar one and never notice the difference. We’ve added quite a bit of complexity: the player has to read two pages of listings and learn what all the abilities mean before they can make an informed decision about their weapon choice. And yet, we’ve added precious little depth: while the high-damage weapons feel different from the mid- and low-damage weapons, everything else feels the same. The feel of gameplay is almost identical to what it was when we only had three weapons.

This is what we must watch out for as designers: just because game options are technically different (complexity), that doesn’t necessarily mean that they feel different (depth). Before adding a layer of complexity to our games, we must ask ourselves whether the resulting gameplay options will feel meaningfully different from each other. If not, we are not creating depth in our game, and we need to seriously consider whether adding that complexity is truly a good idea.

Dice rolling on a white table, by John W. Sheldon.
The creation of depth is the main purpose of complexity. However, sometimes complexity can offer other benefits by reinforcing the theme of your game. For example, intentionally overwhelming your players with complexity can create a sense of panic that might enhance gameplay (a good example of this would be Keep Talking and Nobody Explodes, whose complexity-induced tension is half the point of the game). Alternatively, if your game is meant to be a faithful representation of something else, making sure you cover everything might be worth the complexity even if it’s not reflected in the depth of gameplay (for example, the Elements of Harmony in Tails of Equestria have literally no effect on gameplay, but fans of the source material might have scoffed at an omission).

Complexity is an important part of game design. While some games need complexity to support their themes, its main purpose is as the main source of depth. Designers must decide how much depth they want in their games, figure out how much complexity will be required to get there, and then reconcile the two until our games have sufficient depth without excessive complexity. We’re looking for that sweet spot.

Thanks for reading, and I hope you find these concepts as helpful for your own designs as they’ve been for mine. All the best to you and yours, and best of luck in whatever your next adventure is.

Thank you so much, Jacob, for writing this post and simply sharing some thoughts about complexity!

About the writer: 
Jacob S Kellogg, he/him

Describe your role in the gaming community.  
I'm a fledgling new game designer, and founder of Purple Aether Games.

What do you love about games and gaming?  
I love how games can bring different people together and give them a shared experience, and how it can help people think about things differently.
@JacobSKellogg on Twitter
@JacobSKellogg on Mastodon (
@PurpleAetherLLC on Twitter
@PurpleAetherGames on Mastodon (
Journey Away RPG Kickstarter

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