Psychogeography is an exploration of urban environments that emphasizes playfulness and "drifting". It has links to the Situationist International. Psychogeography was defined in 1955 by Guy Debord as "the study of the precise laws and specific effects of the geographical environment, consciously organized or not, on the emotions and behavior of individuals." Another definition is "a whole toy box full of playful, inventive strategies for exploring cities... just about anything that takes pedestrians off their predictable paths and jolts them into a new awareness of the urban landscape."
Psychogeography was originally developed by the avant-garde movement Lettrist International in the journal Potlatch. The originator of what became known as unitary urbanism, psychogeography, and the dérive was Ivan Chtcheglov, in his highly influential 1953 essay "Formulaire pour un urbanisme nouveau" ("Formulary for a New Urbanism"). The Lettrists' reimagining of the city has its precursors in aspects of Dadaism and Surrealism. The idea of urban wandering relates to the older concept of the flâneur, theorized by Charles Baudelaire. Following Chtcheglov's exclusion from the Lettrists in 1954, Guy Debord and others worked to clarify the concept of unitary urbanism, in a bid to demand a revolutionary approach to architecture. At a conference in Cosio di Arroscia, Italy in 1956, the Lettrists joined the International Movement for an Imaginist Bauhaus to set a proper definition for the idea announced by Gil J. Wolman: "Unitary Urbanism - the synthesis of art and technology that we call for — must be constructed according to certain new values of life, values which now need to be distinguished and disseminated." It demanded the rejection of functional, Euclidean values in architecture, as well as the separation between art and its surroundings. The implication of combining these two negations is that by creating abstraction, one creates art, which, in turn, creates a point of distinction that unitary urbanism insists must be nullified. This confusion is also fundamental to the execution of unitary urbanism as it corrupts one's ability to identify where "function" ends and "play" (the "ludic") begins, resulting in what the Lettrist International and Situationist International believed to be a utopia where one was constantly exploring, free of determining factors.