A study of over 11,000 event rainfall and associated direct runoff events from 100 small watersheds was done, in a search for distinct patterns of runoff response and/or association with land type. Five separate response groups were identified: (1) Inactive, characterized by no recorded responses to any rainstorm in an extended period of record; (2) Complacent, characterized by a very small part of the rainfall (ca 0.1 to 3 percent) being converted to direct runoff, often as a linear response; (3) Standard behavior, the expected 'textbook' response common to agricultural lands and humid sites; (4) Violent behavior, in which an abstraction threshold of 2-6 cm clearly precedes a sudden high response; and (5) Abrupt response in which a very high portion of the rainfall is converted to event runoff without appreciable abstraction, as typified by extensively urbanized drainages. The responses and the group identifications were parameterized by a simple broken-line linear rainfall-runoff equation, and a dichotomous key based on coefficient values is proposed. Only mild associations between response type or coefficient values and the four vegetative covers (Forest, Range, Agriculture, and Urban) were found.