An outerworld is a large grid of rooms, perhaps 1000 by 1000 in which coded areas are embedded. An outer world contains minimal repetitive room descriptions, for example, all forest rooms have the same description. In BatMUD outerworld rooms may contain animals, plants or minerals. An outer world may be expressed, as the latest iteration of BatMUD is, as continents in an ocean. The hex map on DartMUD was an early implementation of mapping which uses ASCII, as do most text-based MUD maps.