Game development is a complex process by which a game is produced. For most people, the computer game experience starts at the store and ends on the couch. Few realize that creating a game can be as complex as making a Hollywood blockbuster. Months of planning and preparation, script writing, casting, character development, cutting-edge technology and massive computing power go into making games. A contemporary entertainment game can take from one to three years to develop, though there are exceptions. : More

Stages in game development

:: The idea
Every game begins with an idea. The idea includes the aim of the game, its educational goals and funny elements. : More

:: Scenario development
The scenario is a detailed description of the idea and the main scenes of the game. : More

:: Storyboard
Once the basic game concept is decided upon, writers and artists work together on a storyboard.
A storyboard consists of rough sketches and technical instructions sequentially organized to depict each scene of the game. It is a visual representation of the story and a reference for the writers, artists and designers just as it would be for a film. But while a film has a single storyline, a video game can have thousands of outcomes. Therefore various levels, or "worlds," of the game must be sketched out.

:: Creating the characters
As the storyboard is made, designers begin to create the characters. : More

:: Putting all in motion
At this stage, the character is basically a digital marionette. The game developpers bring this figure to life by instructing the computer to move the character. : More

:: Game environment
One of the most important aspects of modern game creation is the environment. : More

:: Code
The code is what makes all of the game elements work together, though unseen by the user. : More

:: Postproduction and Testing
Once the game is complete, it enters the postproduction phase. This phase includes extensive testing, review, marketing and finally, distribution. : More

Sources:

:: http://www.pbs.org/kcts/videogamerevolution/inside/how/06.html
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