Examining Appendix B: Random Wilderness Terrain

I'm a big fan of the random tables in the DMG, because I feel that these charts make me less partisan to the development of the scenario.  If the difficulty is being generated more by dice throw than my hand, I don't feel that it's my fault if the PCs are too successful or not successful enough.  Rather, my job is to give the mechanical description some more life and excitement, and to act as a fairly impartial referee with regard to the rules.  Invariably I turn to Appendix A to provide a starting point for stocking my dungeons.  But recently I've been looking more closely at its less-fancied sibling, Appendix B: Random Wilderness Terrain.

The introduction to these tables includes the puzzling instruction that each space can be "1 mile, or larger".  Now, I'm not about to quibble on the shifts in terrain, because the DM is instructed to apply common sense.  My puzzlement stems from the population density generated by the Inhabitation Table - and what that will mean when the scale can be altered.  I did a back-of-the-envelope calculation for just the settlements (setting aside Castle population as too variable for now) and came up with an average of about 411 people per space.  If each space is a square mile, that's a population density slightly greater than that of modern China - hardly the howling emptiness of the World of Greyhawk.  One could massage that figure by saying that large settlements should be prohibited in marshes and mountains, but it's still quite a few people even before considering the land required for the upkeep of the game's monsters.

Taking the space as a 6 mile hex gets a population density of about 17 inhabitants per square mile, somewhat less than modern Russia.  That feels a bit better!  In fact, for most campaigns it's going to be about right once the DM starts applying "common sense" measures like prohibiting towns and cities in overly hostile terrain.  Of course, if you want that full-on post-Apocalyptic D&D style, then maybe try starting with 12 mile hexes and strictly limit settlements off the plain?