[In this in-depth Gamasutra analysis, game professional Breslin examines the history and current state of the 'sandbox game', looking at modern games like Grand Theft Auto IV and Spore to see how they fulfill the concept of unlimited, unfettered creativity.]

It's such a buzzword nowadays -- sandbox. It is a very abstract concept, like "liberty" or "love," so there are a lot of varieties. Modern sandbox games draw from a wide range of design structures: from open-world design to emergent behavior, from automation of believable agents to multi-threaded or non-linear story.

Being applied in such a broad range of situations means that the word "sandbox" risks its meaning becoming watered-down, confused, and sometimes forgotten.

On the other hand, it remains the single most important design issue for current and future generation games. It's a great blessing to spend a while in serious thought, on such a critically defining idea.

Let us take this opportunity, then, to reflect upon the different ideas we as gamers and designers have of the notion. Let us think about where the whole idea came from, and consider where we've come to, as we look toward the many futures of this wonderful little concept.

Just to get rolling, let's consider the concept in abstract:

The Ironies of the Metaphor

The concept of sandbox-style gameplay, as we know, suggests more-or-less undirected free-play. The metaphor is a child playing in a sandbox: the child produces a world from sand, the most basic of material. This in contrast to a game where the upper-level content is presented fully formed and ordered.

The metaphor of "sandbox" suggests something pure and free. It implies that it is a young child in the sandbox (and a pre-videogame child at that, with no toys), and assumes an idealized childhood imagination, an unlimited creativity. It is a good metaphor, and a useful one, but the metaphor is also a little misleading, insofar as it suggests a sort of dream-world imaginative capability of the audience, which is not always justified.

The implications of the metaphor are not necessarily carried over by game designers: we anticipate that less imaginative players will get less out of a sandbox game, and this is fine. But even so, the idea of leveraging the player's imagination is quite ambitious, and more than a little risky.

By itself, this design concept is so ambitious -- "give them a sandbox, and they will build castles" -- that it must be met with a far greater investment in making the sandbox actually work, which generally means much more money and time invested across all levels of production, and particularly upper-level design and writing. It means an especially close relationship between programming and upper-level design, with the anticipation that the upper-level design will often determine the lower-level specifications.

If normal game design is developing upper-level material (missions, etc.) based on an engine, sandbox design is writing an engine to express upper-level gameplay concepts. Of course, it's very silly to put it so simply as that: indeed, game production is always a back-and-forth between programming and design.

But basically, sandbox design requires the development of engines which enable open exploration in various ways, engines which support upper-level sandbox design by providing systems for the handling of the sandbox elements. It's fun work for a systems programmer, but it's not easy. Then, on the upper level, sandbox requires design which emphasizes and encourages free-play, as well as the development and implementation of a wide range of dynamic interactive elements.

And it's not just the presentation of the sandbox elements and the play space, but it's handling all of the player's various interactions, all the possible combinations. To say it very simply, a typical game must respond to correct input, while a sandbox game must reward all input.

While a physical sandbox is very easy to build (compared with most other toys), the sandbox game generally requires far more work than similar, less open and responsive games. Unlike the person who builds a physical sandbox, a sandbox-style game designer cannot simply offload the creative effort onto the gamer.

The Necessary Framework

Unfortunately, sandbox design is sometimes taken to justify the exact opposite: "sandbox" sometimes serves as an excuse for less investment, particularly in high-level design. Sandbox elements can be mistakenly taken as fair replacements of narrative content; indeed, many games have missed their potential because they imagined that free-play would compensate for a lack of narrative. But even for our idealized child, playing around in a physical sandbox gets old pretty quick.

This principle design problem of sandbox-oriented gameplay is already subtly suggested by the sandbox metaphor itself: a child playing in a sandbox needs a lot of direction if they're going to have very much fun. They need toys first, and they need to be given ideas of things they can do with them. The parent needs to provide a meaningful framework. Just dropping a kid in a sandbox does not work.

The same is true of sandbox design. If the design effort fails to produce a game rich in intriguing potential, it's very much like shipping a literal sandbox. -- Imagine a game-box literally filled with sand: the open-minded player might enjoy playing in the sand a bit, but the gameplay really isn't worth a lot.

The necessary framework guides the presentation of the sandbox elements as the world develops and unfolds. This is often expressed as a reward system, which can involve new areas to explore and new stuff to do, more difficult gameplay structures to navigate, more story unfolding, more missions becoming available, and so on. It can be based on exploring the space of the game (exploring Liberty City for example), and it can be based on watching the game-world develop over time.

It often means scattering a great number of narrative elements across the game-world for the player to discover. Rather than presenting the sandbox as "here's a box of toys, goodbye," the framework gives some strategic order to the game's elements, a presentational structure -- and thus it gives the player periodic rewards for playing.

A common misconception is that the stories of sandbox games are not determined by the game's developer: instead, the story is supposedly determined and directed by the player. But even designers of the most free-form sandbox games must specialize in producing worlds which are geared towards making that free-play fun. If the sandbox is interesting (and this is by no means guaranteed!), then the game's potentialities, the potential interest and fun -- including the narrative undercurrent and whatever else makes the free-play engaging and worth the time -- are all very carefully handled by the developer.

"Sandbox" sometimes challenges traditional narrative, but it always puts something new in its place. -- Thus, it does not remove the narrative, but rather transforms predetermined narrative into dynamic, responsive narrative. In other words, the sandbox game distinguished itself by making the responses more significant and meaningful.

This is perhaps contrary to an image of sandbox play which emphasizes pure freedom, but again, sand by itself is not much fun. Automated, complex, and perhaps most of all, directed responsiveness is essential to sandbox play, and the more complex and responsive the world, the more interesting the sandbox.

What is interesting about the sandbox form is not that it allows full freedom, but that it generalizes and parameterizes, it finds arenas for agency and gently crafts the potential space of the game. It fosters a sense of free-play and exploration of that space. It engenders a sense of player control, without actually handing over the reins entirely.