234 THE GAME PRODUCTION HANDBOOK, 2/E
that is refined in iterations, until it becomes a final working version that ships in
the game.
Other things to consider before beginning a prototype (especially a software
one), are the primary objectives and the target audience. For example, will the
prototype demonstrate a vertical slice of gameplay—which entails implementing
elements that provide a representative sample of the final gameplay experience.
This includes key gameplay mechanics with proper play balancing, polished art
assets (including UI, key character models, and a playable level), representa-
tive audio assets, and key demonstrations of technology innovations (for example
physics-based gameplay). A vertical prototype is strongly recommended when
shopping a game to a publisher.
Will the prototype be focused on a specific feature and only be viewed by
members of the development team? For example, is the lead engineer working
on a prototype of the new animation system in order to work out kinks in the en-
gineering and art pipeline? This type of prototype does not need the same level
of detail and polish, can be put together with placeholder assets, and can contain
functional issues that can be addressed later.
While the prototyping process can be roughly categorized into phases, these
phases may not have a distinct beginning and end, especially during iteration.
The process normally begins by defining what is being prototyped. Next, a low-
fidelity prototype is created, based on these initial requirements. The team will
iterate on this prototype. Iteration involves a cycle of specifying the require-
ments, designing something that meets these requirements, evaluating the re-
sults, and starting the cycle over again. There could be several iterations on a
single prototype; the amount is likely dependent on how much time there is in
the schedule.
Once the team is satisfied with the results, they may decide that the feature
or idea is not feasible and discard the prototype, or they may find a new idea they
want to prototype instead, or they may decide to move forward to the next phase
of creating a high-fidelity prototype. This prototype will also go through some
iterations until the team is happy with the results. Once this happens, the proto-
type specifications are frozen and a final version is built on these specifications.
Prototyping can occur at any phase in the development cycle, and the team
should plan to prototype as much as possible. Tight schedules and deadlines may
prohibit much prototyping towards the end of the production phase, so plan to
take advantage of the unscheduled blocks of time that occur in pre-production.
It is better to spend a day or two (or even a week) prototyping key features of
the game, than spending several weeks implementing a feature that ends up
not working as expected in the game. If this happens, there is little time left in
the development schedule to tweak or re-do the feature, and the game may end
up shipping with the feature as is. It is common to work on multiple prototypes
at once—some prototypes may be more complicated (such as a vertical game