A playtest is a session where either developers, testers, or external players gather in a supervised environment to evaluate the gameplay of a game before release.
Playtesting is usually divided between two stages of development:
- Early on, when there are few game assets, but developers are seeking the "fun" of the game and to determine if there will be further development on the project
- Late in development, when external players are brought in to validate the choices the development team has made.
In between those two, playtesting frequently occurs on a regular basis as design decisions are made to further iterate the process.
Note: Playtesting is not the same as Quality Assurance or Test, which is done by in-house or contract employees on a daily basis. QA's job frequently does not involve judging the "fun" of a title, but their responsibilities usually lie in discovering bugs and/or confirming that the bugs have been properly resolved.