Sighting conditions in Harpoon are typically set by the scenario
author. This means there's little guidance to the designer.
Particularly if the scenario spans a large area, it might take several
game hours to resolve, and it would be good to know how conditions
change over time.
The only real game material in the 4.1 rules is on pages 4-16 and
4-17 under 4.5.5. Effects of Weather and Light. One could take this
to imply that lighting thuds from "day" to "night" conditions, since
there's certainly no guidance for anything in between.
On the other hand, the 4.1 quickstart and scenario book includes the
scenario The Gibraltar Question, which has "Dusk is at 1730, with
visibility dropping to 40% and to 25% by 1830". That seems a bit more
reasonable.
Given that we have computers now, can we do this a bit more accurately
when writing scenarios? I will define "twilight" for game purposes as
nautical twilight, the time when the sun is between the horizon and
twelve degrees below. If the sun is above the horizon, it's "day", if
it's more than twelve degrees below, it's "night", and in either case
the standard rules still apply.
One could pick a spot in the middle of the battlefield and use an
on-line calculator (or custom software, easy enough to write) to
generate the transition times. (Even at the equator, a mere fifteen
nautical miles east or west can make a minute's difference in the time
of sunset. Ultimately one really ought to generate lighting conditions
per unit, which could be especially relevant if they're at high
altitude, far from the rest of the battle, or moving fast enough to
beat the sun across the sky, but that's more trouble than I want to go
to.)
In twilight conditions, combine three columns on the sighting
conditions table: "day precip" (in case of rain), "clear day" (for
haze and fog), and "clear night" shifted up one row, so a twilight
with full moon gives you 75% surface range, and a new or below-horizon
moon gives 10%. (And yes, this means you need to know moonrise and
moonset times too.)
(Should you multiply the percentages together or take the worst? The
rules aren't clear. My inclination is to take the worst.)
Spotting modifiers for "night" are applied in twilight, but reduced:
gun flashes or a ship on fire gives ×2 sighting range, running lights
give ×1.5, and missile launches give ×3.
One could get more sophisticated and say that if you're trying to
sight into the sunrise or sunset your effective range is reduced,
while if you're sighting into the reflection of the sun or moon a
silhouette is easier to spot, but I think this is well below
reasonable resolution.
I have written software for this. Here for example are the next few
lighting change events for the game I'm running at the time of
writing:
Time Event State Moon
1997-03-29T18:36:30 now Day -
1997-03-29T18:41:00 Sunset Twilight 3/4
1997-03-29T19:26:00 EENT Night 3/4
1997-03-30T05:03:02 Moonset Night -
1997-03-30T05:41:00 BMNT Twilight -
1997-03-30T06:27:00 Sunrise Day -
Of course, what would be really nice would be a random offshore
weather generator, which given lat/long and time of year would
generate wind/sea state, precipitation and clouds/fog, as well as how
they change over time. But writing that would be a distinctly
challenging task.
Comments on this post are now closed. If you have particular grounds for adding a late comment, comment on a more recent post quoting the URL of this one.