Fog of War

[Sewerbird]

Units should have a 'Spot' attribute, 'Scan Distance' attribute, and a 'Stealth' attribute, and this should determine if you are able to see units at a location and how far Fog of War is turned back. Tiles that are not Visible will have fog of war enabled (a darkening visual effect).

Scan Distance - Determines how many hexes away from the unit is Scannable. Only units in Scannable hexes will have Spot vs. Stealth checks run against them.
Stealth - Determines how difficult a unit to see in a visible hex
Spot - Determines how keen your sight is. Is the attribute used against 'Stealth'

In space, there is no Fog of War, but Stealth & Spot still apply. Every unit in orbit is Scannable by other space units (although must be Spotted to appear). Units in space are not generally considered to be in Scan Distance of the planetside (they don't reveal fog of war from orbit, and planetside units don't see 'up'). However, special space units may be specially allowed to interact with the planetside in ways that ignores fog of war (bombarding obscured hexes, doing directed scans, etc).