Complexity Complex

Originally posted on the Chromed blog here.

Making video games is a complex process. A team of people from many distinct disciplines and with wildly divergent understandings of the world work together on a single project with a single vision. That vision will change as the project goes on, and the changes need to be constantly communicated to all of these specialists in terms that they understand and that will help them contribute their skills to the project.

The product that results is itself complex. Game software is extremely complicated. Commercial game development is one of the last holdouts against the rising tide of managed languages. This close-to-the-silicon code must interpret vast reams of data in a variety of formats, both static and dynamic, and seamlessly converge it all into a single coherent gameplay experience.


With all of this necessary complexity in both the process and the final product-as-a-product, it becomes tempting for game designers to add complexity to their designs for its own sake. This is not, generally speaking, an ideal strategy for game designers to take.

It is extremely important that complexity be paid for. What I mean by “paid for” is this: When a feature increases the complexity of the game, it must generate an improvement for the player that is substantial enough to make learning the more complex mechanism worthwhile.

For an example, let’s compare the control schemes of Street Fighter II Turbo and Mortal Kombat II. Both of these games are 2D fighters, and each has a roster of 12 characters. In each game, players are able to use powerful and tactically valuable special moves, generally by entering a series of commands on the joystick before pressing an attack button.

Of the special moves in each, counting inputs as the same motion if they are symmetrical (for example, a forward quarter circle and a backward quarter circle both count as a quarter circle) yields the following comparison.

In Street Fighter, 11 motions provide 42 moves across the roster. For Mortal Kombat, there are 18 motions needed to perform 52 moves. This gives Street Fighter roughly 3.8 moves per motion, versus the roughly 2.8 moves per motion in Mortal Kombat. So, a well versed Mortal Kombat player will need to learn 7 more motions than a similarly capable Street Fighter player, and each motion he learns will give him access to fewer of the special moves in the game. A novice Street Fighter player has learned roughly 9% of the special moves when he first masters Ryu’s hadouken. By comparison, a novice Mortal Kombat player has only learned about 5% of the moves when he has learned to use Scorpion’s harpoon.

If our hypothetical Mortal Kombat player wants to be able to use the signature finishing moves of the series, he must endeavor to learn 40 motions!* How many finishing moves are there in total? 61. This means that each motion only gives access to 1.525 moves, far fewer than either special move.

Does this more complicated control scheme benefit the Mortal Kombat games? I argue that it does not. The additional complexity makes learning and eventually mastering the game more difficult, while not providing an objectively more rewarding experience. While I grant that other factors may be in play, note that 2011 is the first year that Evo, the national fighting game championship, will feature a Mortal Kombat game in its official line up, while at least one (and frequently more) Street Fighter games have been a part of every championship.

Let me address the most obvious criticism of this thesis. One could argue that simulation games benefit from ever-increasing complexity. I would argue that their complexity is still paid for. For these games, their complexity is a selling point. Their goal is to reproduce some complex phenomenon, and thus their complexity arises from their diligence in that reproduction.

Given the learning curve involved in increasing the complexity of games, designers can make their games more accessible by making sure that their mechanics are as complicated as needed, but do not add large amounts of complexity to provide minor features. If a player cannot understand a mechanic, even if their experience might be better if they did, they will be too busy being frustrated with their lack of comprehension to enjoy the mechanic.

*There is some overlap between the special and finishing moves commands.