An art intervention is an interaction with a previously existing artwork, audience or venue/space. It has the auspice of conceptual art and is commonly a form of performance art. It is associated with the Viennese Actionists, the Dada movement and Neo-Dadaists. It has also been made much use of by the Stuckists to affect perceptions of other artwork which they oppose, and as a protest against an existing intervention.
Although intervention by its very nature carries an implication of subversion, it is now accepted as a legitimate form of art and is often carried out with the endorsement of those in positions of authority over the artwork, audience or venue/space to be intervened in. However, unendorsed (i.e. illicit) interventions are common and lead to debate as to the distinction between art and vandalism . By definition it is a challenge, or at the very least a comment, related to the earlier work or the theme of that work, or to the expectations of a particular audience, and more likely to fulfil that function to its full potential when it is unilateral, although in these instances, it is almost certain that it will be viewed by authorities as unwelcome, if not vandalism, and not art.