The craft of making interactive entertainment is as much about destruction as construction.
Subtractive design - the act of reducing creative clutter – helps to pare a project down to its most effective features, allowing a game’s core aspect room to breathe.
It's also an effective way to deal with the ever-present danger of feature creep, as in the tendency of developers to add feature after feature, until nothing ever gets finished.
The power of subtractive design was made clear while I was developing Vanessa Saint-Pierre Delacroix & Her Nightmare (2010). The game is a simple 2D platformer with one major distinction: Vanessa’s otherwise flat world is mapped to a three-dimensional cube. As Vanessa explores her environment, the player may rotate each face of the cube in ninety degree increments. The effect is something like a cross between Super Mario Bros. (1985) and Rubik’s Cube (1974).
Early on I included a fairly obvious feature that allowed the player to rotate the game’s camera in order to study the cube from different angles. When I tested early builds of the game with some trusted individuals, the outcome was depressing.
Rather than experiencing the enjoyment that comes from directing Vanessa through the environment, players would spend minutes on end studying each face of the cube, searching for a solution to the puzzle without making any moves.
In David J. Sushil's game, Vanessa Saint-Pierre Delacroix & Her Nightmare (screen shot above), camera control was removed to help make the game more enjoyable.
It wasn’t fun.
So, with some reservations ("Players are going to expect to rotate the camera,") I cut the feature. Immediately, feedback improved. By removing an aspect of the design that wasn’t aligned with the game’s core values, the overall experience appreciated.
That is subtractive design at its finest, strengthening a product by removing unnecessary things.
Knowing what to remove from a game’s design is easy in theory but often difficult in practice.
Ask yourself, "Does this feature reflect my game’s basic nature?" If the answer is "Yes," it stays. If "No," it goes.
A typical way to understand how subtractive design works is to imagine that your game is a tree. The sturdiest part - the trunk - represents the most basic aspects of your game. This could include genre (action-puzzle), your central hook (making portals), your plot outline (test subject escapes deadly research facility) and your overall theme (defiance). As you venture outward from the trunk, branches, twigs and leaves represent diminishingly minor aspects of your game.
Portal (2007) would be a strikingly different game if the player suddenly had to manage a typical role-playing game style economy: Kill enemies, collect their stuff, sell it in town, buy better weapons and find tougher enemies.
The biggest branches are usually the easiest to identify as being incompatible with a game’s central core.
If adding role-playing elements to Portal seems like an obviously incompatible design decision that would never see the light of day, consider the case of Brütal Legend (2009). A chief criticism of the game is that it’s genre soup. It can’t decide if it’s an action game, an adventure game, a real-time strategy game, a vehicle sim or a music-rhythm game.
Double Fine's heavy metal-themed genre mashup game, Brütal Legend (2009, Xbox and PS3), is an example of a game that could have been made better by removing unessential and unnecessary elements.
At its core, Brütal Legend is an homage to heavy metal culture. Perhaps dropping the adventure and real-time strategy branches - which have the least elements in common with the game’s central concept - would have strengthened the overall experience of the game.
Of course, there is never a substitute for sufficient testing. The goal of every game developer should be to entertain players. Let their feedback guide (but not rule) your decision-making.
Subtractive design can be applied to every facet of your game. The following sections provide a few examples of how other projects have benefited from subtraction.
Kirby’s Epic Yarn (2010) is a kid-friendly platformer with a subtle puzzle-solving mechanic. The visual style of the game is gorgeous. The world and its inhabitants resemble strings of yarn, knitted patterns, buttons and fabric.
Perhaps the most startling aspect of this Epic Yarn's design is its approach to player death: There is none. Although Kirby can be harassed by a variety of enemies, his health is never affected and he cannot die. There are no lives, no continues and no penalties for making mistakes (except perhaps the loss of a few collected beads, which unlock non-critical game content).
In an interview with Nintendo’s CEO, Saturo Iwata, Kirby’s coordinator, Emi Watanabe demonstrates her proclivity for subtractive design. She states (2010, Iwata Asks: Kirby’s Epic Yarn
), regarding early prototypes of the game:
There were thorns everywhere. There were thorns up above and thorns down below. You'd think someplace was soft and jump down, but an enemy with thorns would be lying in wait. I really liked the yarn motif, so I thought, "Why am I experiencing something so harsh in this fun-looking world of yarn?" I was saying things like, "This isn't what I want to do in this cute world of yarn!"
Nintendo's Kirby franchise did well to eliminate a seemingly standard element of most games in Kirby's Epic Yarn (2010, Wii).
Failure is almost universally accepted as an essential component of a game’s design. While Nintendo’s "E for Everyone" attitude certainly may have influenced the decision to remove player death, it cannot be denied that the threat of punishment stands in antithesis to the game’s conceptual core.
By excluding failure, the overall experience is enhanced.
Subtractive design also becomes apparent in the basic gameplay of other popular titles. For example, in the original version of A Boy and His Blob (1990), the player begins the game with a limited number of jellybeans. Running out of certain flavors will result in situations where the player cannot complete the game. In Majesco’s 2009 remake, the player’s jellybean arsenal never runs out. By allowing the player access to unlimited jellybeans, Majesco created a game that focused squarely on the critical theme of unfettered exploration.
In Part 2 of this article, we will cover how subtractive design can be applied to other aspects of games, including art, audio and narrative.
David J. Sushil is a professor of Game and Simulation Programming at DeVry University. He is also the owner of Bad Pilcrow, an independent game studio in Orlando, Florida. His most recent game, Vanessa Saint-Pierre Delacroix & Her Nightmare, was awarded Best Design in indiePub’s 3rd Independent Game Developers Competition and was a Professional Finalist in the 2011 Indie Game Challenge.