A house organ (also variously known as an in-house magazine, in-house publication, house journal, shop paper, plant paper, or employee magazine) is a magazine or periodical published by a company for its customers or its employees. This name derives from the use of "organ" as referring to a periodical for a special interest group.
House organs come in two types, internal and external. An internal house organ is meant for consumption by the employees of the company as a channel of communication for the management. An external house organ is meant for consumption by the customers of the company, and may be either a free regular newsletter, or an actual commercial product in its own right.
An example of a commercial house organ is the Avalon Hill General. This had no outside advertising (usually a major portion of a magazine's budget). It featured news, strategy articles, variants, and essays on game design—all about Avalon Hill games.