A dune is a hill of loose material - typically sand - created by wind deposition. Dunes are a popular - if somewhat cliched - terrain feature of sandy deserts and are also commonly found in the hinterlands of sandy beaches. Dunes of earth or dust may be found well inland, generally in areas with poor soil and heavy wind erosion. Depending on the environment a dune may be no more than a few feet high or several stories tall.
Many desert dunes are highly transitory, appearing to move down wind as they are erroded and re-deposited, although costal and other forms of dunes can become stabilised by being overgrown with plant life and end up as a semi-permanent part of the costal geography. Unstabilised dunes, on the other hand, can be a serious nuisance and, in the wrong conditions, can migrate into agricultural land and even built up areas causing significant damage.
As little more than piles of semi-coherent material, dunes are difficult terrain - an attempt to gain traction generally leads to sinking into the sand unless your ground pressure is very low indeed. In addition the down-wind face of the dune is typically highly unstable and prone to avalanches of sand if disturbed.
Game and Story Use
- A useful bit of terrain in the right circumstances - the deep desert dune field is an obvious one, but costal dunes are overlooked as an environment: for anyone crossing a beach covertly a dune field provides useful cover and concealment.
- Whereas the effect of encountering a dune outside a sandy environment can be quite impressive: the first time encountering a soil dune in the mountains for example is something of a surprise.
- The marching dunes make for a good imminent apocalypse for a civilisation on the edge of the desert - and more so for an RPG if unnatural forces are at work.
- Likewise, the idea of a city buried by marching dunes - and that which is buried can be unburied just as swiftly.