This article groups together a small number of films made at the London Filmmakers’ Co-operative in the first half of the 1970s, primarily by film-makers such as Chris Welsby and William Raban, who are more typically discussed in relation to the category of "landscape films." The films discussed here explore the restrictive and expansive possibilities of systems, constraints and procedural processes. They often resemble other experimental films that deploy repetition, but they are distinguished by the following feature: the consistent use of predetermined rules and prescripts; in-camera editing that either follows preselected schema and set procedures or breaks from these for specific reasons; and causal mechanisms, often requiring the film-maker to react to events occurring at a specific site. These practices draw from and contribute to a broader interest in systems-oriented and constraint-based processes that also encompass literature and painting. Consequently, this study looks at two collectives, Oulipo and the Systems Group, in order to provide a more period-specific contextualization of this tendency within the Co-op. Linking together much of this work are beliefs and attitudes such as the resistance to romantic notions of creative activity and the view that the artwork’s form is more than simply a static construct.