The Difference Between Complexity and Depth in Video Games

Video games can be simple or complex, deep or shallow, and all different combinations of those terms. None of these various permutations are necessarily bad, just different.

If we were to understand video games as a language, the level of its complexity would be in its syntax, while the level of depth would be in its semantics. Today I will demonstrate the difference between "complex vs. simple" and "deep vs. shallow" dualities and I will offer some examples of combinations between these terms in videogames.

When I say complexity is a syntactical concept, I'm saying that it has to do with a number of elements and a number of relations between those elements. Several areas (such as logic, philosophy, linguistics, and computer science) use the concept of complexity to describe an aspect of a system. In addition, several areas of art and knowledge also use the concept of depth to describe another aspect of a system, not an aspect of its syntax (structural order), but the meanings attributed to its elements and relations. This syntax-semantic duality will be the key to explaining the terms of this essay.

Syntax and Complexity of Video Games

A didactic way of understanding syntax is through Chomsky's linguistic definition, in Syntactic Structures (1957). In his terms, the syntax of a system is nothing more than an alphabet plus grammar, which prescribes how to construct well-formed expressions with the alphabet. This Chomsky definition can be generalized to systems. Thus, the syntax is a set of primary elements of a system plus a set of rules for establishing appropriate relations between these elements.

In these terms, what would be a complex system? Well, one way to understand, via Complexity Theory, is as a system that is on the border between what is considered "cyclic" and what is considered "chaotic". Christopher Langton, in Artificial Life: An Overview (1995), separates systems into four degrees of complexity:

• Fixed systems (whose relations between elements are immutable);
• Cyclic systems (whose relations between elements repeat infinitely simple patterns);
• Complex systems (whose relations are in constant motion, sometimes unexpectedly);
• Chaotic systems (whose relations are highly unpredictable and with random changes).

Practically all video games we know are complex systems, but we can see that some are more complex than others. In this sense, it is possible to understand the level of complexity of a system as the level of relations established between its elements. If we are analyzing a story, we can understand as primary elements of our analysis things like its characters, the settings in which they pass, and the vocabulary used in the text. Thus, a story is as complex as the number of relations established between these elements.

The Netflix series Dark (2017-2020), directed by Baran bo Odar, has a very complex plot, because there are several relations (previousness, posterity, causality, kinship, etc.) established between its characters, dialogues and scenarios. Similarly, we can also say that the plot of video game series like Chrono and Kingdom Hearts are also quite complex, whose worlds were written, respectively, by Masato Kato and by Tetsuya Nomura. In contrast, Inside (2016), directed by Arnt Jensen, is extremely simple in terms of its plot. There are very few characters and few relations between them, few settings, and no dialogue.

But the concept of complexity is not limited to the plot. We can also apply this concept to characterize mechanically complex video games. From a mechanics point of view, for example, ICO (2001), directed by Fumito Ueda, is an extremely simple video game. Practically, the gameplay can be summarized in walking, moving a few types of objects, attacking in a standard combo using a stick, and guiding a second character. In contrast, Final Fantasy XII (2006), directed by Hiroyuki Ito and Hiroshi Minagawa, is certainly not a simple game, having many more mechanics in systems and subsystems, such as Active Dimension Battle (ADB) system, Quickening (Limit Break system variant), Gambit system, Zodiac Jobs system and License Board.

This simple-complex duality in syntactic terms of "video game language", can also be applied to soundtrack, level design, and other game design areas, although my purpose here is not to be exhaustive in the examples and applications. The important thing to note is that a video game being "simple" or "complex" does not imply being shallow or deep, and this I will demonstrate in the next topic.

Semantics and Depth of Video Games

However, video games are not just complex systems, they are complex systems whose internal relations have external meaning. That is, interpretants and developers establish external relations with the system, attributing meanings to it. This is why Katie Salen and Erice Zimmerman, in Rules of Play: Game Design Fundamentals (2003), claim that games can be understood as meaningful play.

Returning to our understanding of video games as a language, this set of "external relations" that assign meanings to the elements and relationships of the system can be understood as semantics for the system. In this sense, both when we develop a game and when we play it, we are not just building or operating systems, but we are giving or interpreting meanings.

One way of understanding meaning is via a theory of reference, as in Frege's theory of the relationship between sense, meaning, and reference in On Sense and Reference (1892). In this way, we can say that a phrase used by a character or a mechanic or even an image has "meaning" insofar as it refers to something external to the word, mechanics, etc. There is a lot of detail, and a long debate on how to apply "meaning" outside linguistic discourse (textual or spoken) and in fictional works, but it is impossible to give the necessary space to this issue here.

So, I'm going to assume here that, yes, somehow image, mechanics, and other things can also be associated with some meaning, which can be understood by player interpretation. Furthermore, I am assuming Frege's difference between sense and reference. That is, for something (a sign) to have meaning, that something has a reference and a sense. In the first case (reference), it has to do with an "object external" to the signifying term; in the second case (sense), it has to do with the "mode of presentation" of the reference.

In ICO, for example, the fact that the protagonist is a boy and has a simple attack with a stick is not a set of random choices by the developers, they designed it as an accessible presentation mode to make reference to the fragility and inexperience of the character's actions. Similarly, when in the ending of Chrono Cross we see real footage with a person similar to the character Kid, this design choice is a way of presenting the idea that there is this character in other timelines, even referencing it in the timeline we live in.

Note that in many cases there are terms that can have the same reference. For example, in the Kingdom Hearts series, one might say "Roxas is in Twilight Town" and "the Nobody of Sora is in Twilight Town". The terms "Roxas" and "the Nobody of Sora" have the same reference, they refer to the same character, but have different senses, differing modes of presenting this reference.

OK. Considering this framework, how can we understand the notion of "depth" of a work? Simple, as it's analogous to complexity. A work's level of depth is proportional to the number of senses and references presented in the work. Game design elements are more deeply dense the more polysemic they are, but in a controlled, not chaotic way. When a writer, for example, uses an ambiguous word and plays with its multiple meanings, he is increasing the depth of his text. Disco Elysium (2019), directed by Robert Kurvitz, is a good example of textual depth in video games. And this can be used in other areas of game design as well, not just words.

In this sense, sometimes a simple mechanic, like holding a girl's hand to guide her in ICO, can have many meanings attached to it. That action forces the player to take care of the character, having to manually press a button to do so, and thus creates a bond between characters and player. In fact, ICO is an experience with a very dense depth in almost all of its elements, and this is due to Design by Subtraction, which I have already written about here at SUPERJUMP: The Definition of Design by Subtraction (2021).

Combinations of complexity and depth in game design

Having made the necessary clarifications about the difference between simple-complex vs. shallow-deep, it follows that these dualities are independent. It is possible for a video game to be

1. simple and deep;
2. complex and deep;
3. complex and shallow;
4. simple and shallow.

Simple and deep games often use Design by Subtraction to create dense experiences, saying a lot through a few elements, like Inside and ICO. In contrast, complex and shallow games tend to use something like a "design by addition", as I like to call it, based on the assumption that the addition of more elements, even if not very significant (in semantics), enriches the player's experience, if the implementations are functional. An example of this in terms of narrative is the Kingdom Hearts series, an example of this in terms of level design is the Grand Theft Auto series, and examples in terms of mechanics abound in strategy games.

On the other hand, complex and deep games usually try to use the complexity of their systems to their advantage to express ideas that could hardly be communicated with just a few elements. Some political concepts, for example, are hardly represented well without there being several characters and/or countries involved in the game's story.

That's why some TRPGs like Final Fantasy Tactics (1997/2007) and Tactics Ogre (1995/2010), directed by Yasumi Matsuno, are good examples of video games that are both complex and deep. Conversely, classics like Doom (1993), Super Mario Bros. (1983), and Tetris (1984) are great examples of simple and shallow games that say little through few elements, but enough to show the player that the focus of these games is on inventiveness or the impact of the interaction itself of their mechanics, and not so much what they mean.

Whichever way you choose to make a video game, the execution of your proposal can be good or bad, and that's what will matter most to please the audience for that proposal. You need to first be clear about what the purpose of your video game will be, and only then, during development, do you question how complex or deep it needs to be.