There is a great deal of debate about how to define the term "alternate reality game" and what should be included or excluded by the definition. Sean Stacey, founder of the website Unfiction, has suggested that the best way to define the genre was not to define it, and instead locate each game on three axes (ruleset, authorship and coherence) in a sphere of "chaotic fiction" that would include works such as the Uncyclopedia and street games like SF0 as well.[2]
If one accepts noted game designer Chris Crawford's definition of a game (it requires that there is an opponent), then ARGs are perhaps better understood as puzzles. However, if the puppetmasters are actively changing the game while it is going on (as happened with The Beast), then the ARG does more closely fit the definition of a game.
While addressing all of the various attempts at definitions and arguments for and against them is beyond the scope of this article, defining a few terms unique to ARG parlance, identifying precursors and influences on the development of the genre, and comparing and contrasting ARGs to other similar forms of entertainment may be helpful in aiding understanding of the form.