Harold

Developed by Del Close at iO (formerly ImprovOlympic) in Chicago during the 1980s, the Harold is a long-form improvisation structure in which an ensemble of performers takes a single audience suggestion and builds an extended, interconnected piece from it. The format typically begins with an opening (such as a monologue, pattern game, or invocation) that mines the suggestion for themes and associations. From this opening, three separate scene threads emerge, each revisited and heightened across multiple beats. Between these beats, performers execute group games that further explore the suggestion's thematic territory. As the Harold progresses, connections surface organically between the seemingly unrelated threads, with characters, themes, or ideas from one storyline weaving into another. The result is a layered, ensemble-driven piece that rewards patience and trust among its performers. The Harold became the foundational long-form structure taught at iO and has since influenced virtually every long-form format that followed, serving as both a training framework and a performance vehicle for house teams worldwide.