Scale system to use

[BlackJaw]

Also important to decide is what scale to use.

1) A single large scale. Starwars d20 uses a 500meter/square scale. Most ships are one square, and the really big ones are 2 squares.
Pros: A grid represents a lot of space, ships can move realisticaly fast, and weapons have have realisticaly long ranges. because everything is in one scale, it is fast and easy to use.
Cons: works fine for space crafts, but not for air, and not for when you need ships to interact with non-ships. It also doesn't work for monsters and spell effects etc.

2) A few "levels." Space uses a large scale, atmosphere is 1/10th that. Any craft, mosnter, spell, item, etc that allows flight in both air and space simply increases in scale also. Thus a Void Dragon that lands on a planet goes from 600' to 60' but still moves at say 3 grid spaces. This system is used by Dragonstar, and is OGC.
Pros: works well without to much converting from one scale to another, and is fast and easy in play as things from one scale can not interact with things in another scale.
Cons: not that realistic, and by setting a scale, even having two to switch between, it is still a little odd for somethings to interact with.

3) Undefined system. Many ranges and speeds are given in "squares" or in feet, but at no time is a spicific grid ratio stated. DMs set that as needed.
Pros: flexible. It will work for the largest space battles and also two guys with fly spells.
Cons: converting takes place a lot, and can slow down the game.

[Wyvern]

I voted "none of the above", because the system I suggested in my draft doesn't sound quite like any of the three you described, unless I'm misunderstanding you. Using my system, 30' is a recommended *default*, but GMs could shift to higher scales if necessary, picking whatever is most appropriate for the situation. The actual speed of creatures and ships is measured in absolute terms (not "spaces"), and doesn't change when you shift from one scale to another. So a 60' dragon with a 150' move would take up two spaces and move five spaces per round on the 30' grid. On a 300' grid that same dragon would be a pinpoint and move only half a space per round. It's not as complicated as it sounds because you'd rarely use two different grid scales in the same setting, let alone the same battle.

Wyvern