How far can the party see?
I've been noodling around with a STALKER inspired OSR game, which has had me thinking about sightlines for hex crawls. For my purposes I've been using 3 mile hexes because so much of the maths around hiking works out well.
With 20:20 vision you can spot a person as a dot for about 1.5 miles (½ hex) and a 6ft square object (e.g. a car) for about 3 miles (1 hex). With a scope you can theoretically make out details at magnification X that distance (but you'd need sufficient elevation and clear weather).
You can see further when higher up. Assuming flat ground and a clear day, here's how far you can see the ground from different heights:
| Height | Equivalent to | Horizon Distance | Looking out a window on the... |
|---|---|---|---|
| 1-3 ft | Lying Prone / Crouching | ~ 1.5 miles (0.5 hex) | Ground floor |
| 6 ft | Standing | ~ 3 miles (1 hex) | Ground floor |
| 12 ft | Standing on a car | ~ 4.5 miles (1.5 hex) | 2nd floor |
| 30ft | Roof of a two storey house / top of a telephone pole | ~ 6 miles (2 hexes) | 3rd floor |
| 90ft | Water tower / church steeple | ~ 12 miles (4 hexes) | 9th floor |
You can assume every 30ft of additional elevation (approximately 3 stories) will let you see another 3 miles (1 hex).
If you're wondering, the effects of atmospheric haze on a perfect day would be minimal, with elevation being the limiting factor. On a perfect day you could see 150 miles, so you'd need to be at a height of about 15,000 feet.
