I'm working on a top-down map of a world for a fantasy RPG campaign. Exactly HOW to properly represent that map has been a royal headache. I'd like to define my parameters in advance so I don't have to keep changing formats over and over.

Thus far I've been convinced that the 6-mile hex is a good starting point. I figure I can represent the world map in an icosahedral format using 216-mile hexes, 20-24 hexes wide per face depending on how the hexes are oriented.

Assuming that approach is sensible, and I'm not certain that it is, I still have a number of questions:

What are the reasons for choosing to orient the hexes vertically vs. horizontally? Advantages/disadvantages? Is it a factor that comes into play when subdividing hexes into smaller sub-hexes?

When subdividing hexes into smaller sub-hexes, what are the advantages/disadvantages to different subdivision methods? Better to have a centered sub-hex or a vertex at the center of the larger hex? This is also raises questions on how the hexes are laid down on the icosahedron.

Once these issues are resolved, I need to select a mapping program. Hexographer looks about right for my needs although I need to play with the free version more to be sure. Does anyone know if I can modify the number of hexes per face used in their icosahedral map? Change the hex orientation?

Any help would be appreciated.