"ARGs are games that are driven by storyline and typically supported through some type of online game portal that manages the game.
Playing the game, however, requires that you interact with characters, other players, and storyline elements that might be online, but may also be found in aspects of your "real" life.
Websites, social media tools, media broadcasts, phone calls, text messages, and sometimes person-to-person interactions are all potential elements that move the storyline along."
--Koreen Olbrish, The ABC's of ARGs: Alternate Reality Games for Learning