Illumination's Effect on Missile Weapons

This table is from the Authentic wiki, and details the range of thrown and fired missile weapons according to the number of 5 foot hexes.  For game purposes, a missile weapon cannot be thrown at a range of 1 hex, because it is supposed that the enemy would be close enough to foul your attempt, since at that range you would be in hand-to-hand combat.  At a range of 2 hexes, "point blank" (and I suppose I could call it "close" range), the attacker is +1 to hit with the weapon.  At short range there is no adjustment; the attacker is -2 to hit at medium range and -5 to hit at long range.  These are not my adjustments; they were invented for AD&D.

So, for example, if the character were to throw a hand axe at  7 hexes, that would count as medium range.  7 hexes would be short range for a crossbow and it would be long range for a short hammer, which is essentially a carpenter's hammer.  This difference in range is a factor in balancing the decision to take one weapon over another when a character selects their proficiencies.

These adjustments assume the light of day and that has always been an insurmountable problem: what, for example, is the range on a light crossbow underground, when the party is carrying a lantern which illuminates to a distance of 30 ft.?  The light of that lantern does not just come to an end, so that everything is in full dark beyond that distance.  Anyone who has been outside at night, or in a very large enclosed room in the dark, like a gymnasium, knows that as eyes adjust, and as reflection from the far walls begins to affect the scattering of visible light, that the distribution of light is not a fixed distance from a lantern or torch.  Presumedly, there is some light out there; and if there is light, there ought to be some chance of seeing an enemy move, and of hitting that enemy.

[likewise, how is infravision managed beyond the nominal limitation of 60 ft., as described in AD&D?  I don't know if 3e or 5e addressed this problem; but I still question how infravision, which exists in natural light, even if we can't see it, diminishes with distance]

But how is this diminishment of light managed?  For the most part, it isn't; we accept the premise that fighting in the dark will be hand-to-hand, and that if someone is standing outside the range of light or of infravision, that they cannot be attacked with missile weapons.  I'm unsatisfied with this, not least because having stood outside in starlight in the country, without so much as a porchlight in the distance, while conducting amateur astronomy so that I am out in it for hours, it has been perfectly feasible to see across a field of wheat and see someone stepping out of the trees there.

The problem would be to identify individual ranges for each weapon for proposed levels of illumination; such as, "dusk," "full moonlight," "dim moonlight," "starlight" or "full dark," the last of which would be under overcast skies, or in dense forest conditions, when it becomes so dark that one can barely see their hand in front of their face.  I've experienced that many times.

That's a lot of tables and I think would be impossibly inconvenient.  What would be needed is a shortcut of some kind.  Which, insanely, I've invented.

As visible light diminishes, the quantifiable range of missile weapons declines.  The Modifier Adjustment Table, below, provides a proportional conversion for how a given range in combat hexes is affected as the intensity of light diminishes.

The adjustments indicated above are not meant to affect the actual distance that a weapon can be aimed or fired. Instead, the adjustment indicates how the distance should be treated when rolling to hit. All weapons suffer a penalty to hit according to their range, indicated on the missile ranges table. Ranges are divided into point blank, short, medium and long. In full light (FL), weapons thrown or fired at point blank range are +1 to hit; for short range, there is no adjustment; medium range gives a -2 penalty; long range, a -5 penalty.

For example, a warhammer normally has a short range of 3-5 hexes and a medium range of 6-8 hexes. However, if we imagine the combatant is throwing the hammer in full moonlight conditions (FMC), then according to the table above, a range of "3 FL" equals 4 FMC.  The thrown hammer would still be treated as "short." However, a range of 4 FL equals "6 FMC," so that the medium-range penalty of -2 is applied. A range of 8 FL counts as "13 FMC," so the hammer would be -5 to hit.

"13 FMC" refers only to the difficulty to hit and is not a measure of the weapon's actual range! A warhammer in full light has a maximum range of 11 — and so some may misconstrue the Modifier Adjustment Table to mean the hammer cannot be thrown at 8 hexes in FMC. It only means that the range modifier is adjusted, not the actual range. The hammer would still be able to be thrown to a distance of 11 hexes, but would count as being long range between 8-11 hexes.

Where FL indicates a range spread, such as "28-30," then anything in that range is adjusted as shown.

Where a dash (–) appears on the chart, regardless of the weapon's possible range, count any attempted attack at that distance in those light conditions as a miss. The indicator means that at this distance, nothing whatsoever can be seen; this applies as much to the casting of spells as it does to missile weapons.

I trust that's clear enough.  Let me know.

Incidentally, the same chart helps establish details in situations where the party is meeting someone in the dark, or the distance at which encounters under these conditions would be engaged.