RLM stands for Relief Level measurement and is used to measure the average roughness of a planet's terrain. It is used by a number of planets in the lower areas of the Dendrius galaxy.
It was first invented by the Duelliki, when they were looking at planets to invade. Before launching a colonization attempt or an invasion, they first had to provide a detailed analysis of the terrain of the planet before then working out which machines to use. This system was devised so that this process became as simple as looking at the classfication (which had been done in advance) and then activating the machines that were effective at that level.
There are six levels of RLM:
- The terrain is almost completely flat, with very few or no mountains at all.
- Much like 1, only perhaps with at least 10 mountains and the average terrain is a little more rough.
- At least 25 mountains, with a higher average height.
- Around 60 mountains. The terrain is somewhat difficult to maneouvre about in.
- Up to 160 mountains and the terrain is very bumpy and rocky. The native species have devised special equipment to get around.
- More than 160 mountains, incredibly bumpy terrain.
No planet of RLM: 6 has ever been detected by any species in the Lower Sector.