Sources of Gameplay – Assets Versus Emergent Behavior

June 26, 2015

The first fully realized computer game I ever created was Quack V. It was a simple first person shooter that I started on early in 2006 and released late in that same year. I’d created a few other small games before that, but Quack V was the first thing that had everything expected of a modern computer game: graphics, sound, music, remappable controls, and so on.

I picked an FPS as my first game because they’re simple. Most of the work is in the programming – figuring out how to render levels and characters, have enemies chase the player, respond to the player’s actions – all that sort of stuff. However, I was merely laying the technological foundation for the type of game I really wanted to create: an adventure game.

Flip the calendar to 2014. Having dabbled with a few other small gaming projects, I was ready to jump into the first Sleuthhounds computer adventure game, The Unlocked Room. At first glance one would think that such a game would be simpler to create than an FPS. It doesn’t have fast moving graphics. It doesn’t require complex 3D geometry or math calculations. In fact, being a point-n-click game, its interface could be described as nothing more than an elaborate menu system.

The complexity of an adventure game lies not necessarily in the programming (although the Sleuthhounds games are the most technically complex pieces of software I’ve ever developed), but rather in what that programming connects: the game assets. The game assets are all those data, image, and audio files that make the game what it is. It’s fair to say that most games are concerned with the management of large quantities of data rather than arcane game programming voodoo magic.

To illustrate the point let’s compare Quack V, the first person shooter, with Sleuthhounds: The Unlocked Room.

Quack V Sleuthhounds
Graphics (sprites, interface images, etc.) 199 593
Audio (music, voices, sound effects) 24 682
Game Logic 15 27
Miscellaneous 1 46

As can be seen, there’s a significant jump in game assets all across the board from the simple FPS to the adventure game. Both of these games can be completed in about half an hour on a first play through. Yet, the fundamental differences in their designs require a greater number of game assets in an adventure than an FPS.

An FPS game, like most action games, gets its gameplay from “emergent behavior”. For example, the enemies in Quack V are given basic rules on how to move and how to throw eggs (yes, you read that right, eggs) at the player. They’re then turned loose. As the designer, I know what rules they’re following but how those rules are interpreted by each enemy is based on where that enemy is in the game world, whether they can see the player, where they’re currently moving to, where they’re currently moving from, and several other variables. These factors mean that the same rules will produce different behavior and so a slightly different challenge each time the game is played.

In contrast, my adventure games are like most adventure games, heavily dependent on story. If you read a novel and then you reread it, it’s the same words in the same order. An adventure game is much like that. Yes, there may be some tasks in the adventure game that you can choose to do in a different order each time you play, but those tasks are still always dictated by the story and usually all have to be done to progress regardless of the specific order. The opportunity for emergent behavior doesn’t exist to the extent that it does for an FPS.

Since story driven adventure games don’t work on the principle of emergent behavior any interactions that the player can make within the game must be specifically implemented. Consider the very first screen in Sleuthhounds: The Unlocked Room.

[Sleuthhounds: The Unlocked Room]
Sleuthhounds: The Unlocked Room

Here the player must free Pureluck Homes by taking the badge from Pureluck’s coat and using it to pick the lock of the manacles (oh, um, spoiler). It’s a simple puzzle to ease players into the game. Most players I’ve observed go straight to the solution.

However, even this simple scene allows players to look at the cuffs holding Pureluck, pull on the chains, examine Pureluck himself, examine the room/wall behind Pureluck, and so forth. Each of those interactions has its own custom response. Pureluck will say something different in response to each of those attempts. So right there are a handful of lines of dialog, each of which requires a recorded audio file. And none of those attempts even have any special animation associated with them.

Even in as short an adventure game as The Unlocked Room, Pureluck has a total of 27 separate animations. Whether it’s simply walking around a room or attempting to push a crate, each of those animations consists of a series of separate images shown in quick succession. Twenty-two images exist for Pureluck to speak. Twenty-six images exist for him to stand and walk.

Every game has its own challenges. For a 3D FPS game, the challenge is more on the programming side, dealing with 3D geometry and movement. For an adventure game, the challenge comes from the sheer quantity of distinct assets needed. In either case, the goal remains the same: to provide players with a quality gaming experience.