An irregular open-field system is a collection of unenclosed fields randomly dispersed with individual holdings unsystematically distributed through different parts of a township. Although they appear widely distributed throughout England they tend to concentrate more in those areas characterised by hamlets and isolated farmsteads rather than villages.
Irregular open-field systems may be distinguished from regular open examples by the nature of their distribution. Regular arrangements appear organised while examples of this class display no such pattern of apparently systematic growth or development. As an open-field system it may be distinguished from enclosed examples in terms of the layout and general appearance of the fields. In open-field systems unbounded plots are contained within a bounded whole, enclosed for example within a parish or township boundary. In enclosed field systems the individual plots are enclosed giving the appearance of a more densely packed landscape.
The distinction between regular and irregular open-field systems is, however, only a morphological one. In terms of management the difference was never very great. Land was cropped on a three course rotation in the irregular fields while a variety of land-use policies were pursued within the supposed constraints of a two or three field system (Dyer 1988,27).
The essence of the open-field system was, therefore, that the resources were distributed among the inhabitants in a way which necessitated co-operation. The amount of co-operation was to a certain extent indicative of the degree to which critical resources were under pressure (Astill 1988,63). An important feature of the open-field system was the proportion of arable to pasture and, related to that, the need to ensure soil fertility. A common response to these requirements was to divide arable areas into two, three or even four fields in each of which every villager had his holdings distributed. Within this class one such configuration is known as solskifte (sun pattern) and was often a reflection of the way tofts were arranged in the village.
Irregular open-field systems should not be isolated from the social context in which they existed. Roberts (1987,50) defines this as the "village idea" in which village morphology, social status, field layout and tenurial arrangements are all locked together into a coherent whole.