# How far does the direct light of the Companion reach?

In the Baldur's Gate: Descent into Avernus module, the Companion is an object that has saved Elturel in the past, and is now in the process of dooming the city. I'm the DM for a BG:DiA party that has just arrived in Elturel, and am planning ahead for after-module adventure hooks if they manage to rescue the city.

As such, and since I don't know the 'maths', I'm curious as to how far the direct light of the Companion would reach from Elturel because Chapter 1 states that:

all lands falling under the light of the Companion are forfeit to Zariel

The module doesn't state how far said light can be seen from what I can tell, but there is some information on the Companion that can be found in the 'Dealing with the Companion' section of Chapter 5. From this section, we know that the Companion is

…a nearly indestructible metal orb 50 feet in diameter... which is surrounded by a 400-foot-diameter, 10-foot-thick shell of impenetrable, magical darkness.

Since this darkness never touches anything in Elturel, that means that the Companion is well over 200 feet above the highest point in Elturel. This point would be High Hall, which itself is at least 55 feet tall based on information found in the Chapter 2: High Hall sidebar. Unfortunately, I can't find anywhere that states how tall the cliff is that High Hall sits on. If we assume that the Companion has a near-sunlight brightness and is 500 feet above the ground in the center of Elturel:

How far does the direct light of the Companion reach?

The description of the Companion in the Sword Coast Adventurer's Guide (p. 81) states:

[...] This constant daylight lessens the further one travels from Elturel, casting a sort of wan dawn light for fifty or so miles around the city. Beyond that, the orb is visible as a bright beacon in the sky. It can be seen clearly at night from as far away as Boareskyr Bridge and Berdusk, looking like an unmoving star low on the horizon. [...]

In addition, the description of Elturel in the Hoard of the Dragon Queen adventure (p. 28) mentions this about the Companion's light:

This light [...] is visible from almost every corner of Elturgard (of which Elturel is the capital), appearing from afar as a star or distant sun.

## How far does the direct light reach?

D&D is not a physics simulator; we have no basis to decide how far the light from the Companion can actually reach. Does light propagate infinitely in a vacuum? How much light is absorbed by the atmosphere of Faerûn? How curved is the surface of the planet? How greatly does the gravity of the planet curve the path of the light? We simply don't, and can't, know these things. We do have citations for how far the light can be seen, though.

## From how far can the light be seen?

The direct light which comes from the Companion can be seen for miles, as the quotes from Raj's answer demonstrate. As a light source, it is more easily visible at night than in the day. Within fifty miles of Elturel the land is in constant daylight due to the light of the Companion. Beyond that the Companion is visible at night "as a bright beacon in the sky" and can be seen from "as far away as Boareskyr Bridge and Berdusk, looking like an unmoving star low on the horizon." According to the Sword Coast map in Rise of Tiamat, both Boraresky Bridge and Berdusk are approximately 125 miles from Elturel. Baldur's Gate is approximately 150 miles from Elturel and the same passage implies that the light of the Companion cannot be seen from that city. BG: DiA (10) further says:

Given the distance between the two cities, it's no surprise that the residents of Baldur's Gate didn't hear of Elturel's fate until refugees from Elturgard started arriving in droves.

This passage also implies that the light of the Companion cannot be seen in Baldur's Gate, since otherwise BG would have known immediately that something was amiss when the Companion went dark. However, as you note, the Companion is perhaps 500 feet above the city. At the furthest extent where it can be seen it is "low on the horizon". Whether it cannot be seen from Baldur's Gate because the light itself doesn't reach that far, because it is below the horizon of the curved surface of the planet, due to some local topography of the Chionthar River Valley, or some combination of the three, we are not told.

### However, the light itself does not determine what is 'under it'

"All lands falling under the light of the Companion..." is not meant to imply that

Zariel

is now the master of Berdusk simply because the light from the Companion can be seen in that city. 'Under' is used here in a metaphorical sense of political subordination,

as befits a contract drawn up by Lawful Evil devil.

The passage continues "All persons bound by oath to defend Elturel are also considered forfeit," and we are told that by the Oath of the Creed Resolute this means all the citizens of Elturgard1.

Thavius was proclaimed High Overseer of Elturel after he summoned the Companion to save the city. In some sense, the Companion is a symbol of his office. 'All lands falling under the light of the Companion' is referring to his leadership, and to the oath the citizens of Elturgurd swore. Thus 'all lands falling under' is a political reference to the lands of Elturgurd, and does not refer literally to the places where the actual light of the Companion can be seen.

Note also:

Zariel is desirous of the souls in all the land so as to turn them into lemures and then promote them to devils to fight in the Blood Wars (cf. 150, 243). While the Oath of the Creed Resolute means that all citizens of Eltugurd are now hers, she likely dragged only the city of Elturel (see map 2.1) to Avernus because it had the highest population density. Compared to its hinterland, the amount of souls she could harvest from the city measured against the power needed to rip the land from the Material Plane resulted in the greatest Return on Investment when taking the city to just beyond its own walls. Citizens who were outside the city when it fell are still forfeit, but it is more trouble for her than they are worth to collect them.

1Properly speaking, Elturel is the city and Elturgard is the land, but these are used somewhat interchangeably. For example, in BG: DiA we are first told (47) that the citizens of Elturel swear to defend Elturgurd, but later told (64) that the citizens of Elturgurd swear to defend Elturel.