Does pointing a bullseye lantern away from you illuminate you as well, or keep you in darkness?

Question

Suppose my character is in darkness. I light up a bullseye lantern:

A bullseye lantern casts bright light in a 60-foot cone and dim light for an additional 60 feet. [...]

If I point the bullseye lantern away from me, is my character illuminated in any way? Am I included in the cone of light, or am I outside of the cone, like when casting the Cone of Cold spell?

If I remain in darkness when using a bullseye lantern, then I could remain unseen to those without darkvision, while illuminating my enemies.

Answer 1

From PHB, p. 204:

A cone’s point of origin is not included in the cone’s area of effect, unless you decide otherwise.

However, the point of origin of a continuous effect, such as light, is definitely identifiable. You would therefore not be "invisible" as your location is clearly defined by the hand holding the lantern even though you are holding it out in front of you.

Most of your body would be "heavily obscured" RAW, though note that some GMs reasonably rule that the space of the bullseye lantern (the cone's point of origin) is also considered dimly lit.

Answer 2

You decide

Since

A bullseye lantern casts bright light in a 60-foot cone and dim light for an additional 60 feet. Once lit, it burns for 6 hours on a flask (1 pint) of oil.

(emphasis mine), and

A cone’s point of origin is not included in the cone’s area of effect, unless you decide otherwise.

(emphasis mine)

If I point the bullseye lantern away from me, is my character illuminated in any way? Am I included in the cone of light, or am I outside of the cone, like when casting the Cone of Cold spell?

The rules say, you decide.

If I remain in darkness when using a Bullseye Lantern, then I can remain unseen to those without dark vision, while illuminating my enemies.

That is correct. Which begs the question, why? There are two obvious benefits from being in heavy obscurity, gaining the benefit of being an unseen attacker and target and achieving surprise.

Benefit from heavy obscurity

If you do not have darkvision, and neither do your enemies, and the bullseye lantern is the only source of light, then benefit from being an unseen attacker and target.

When you attack a target that you can’t see, you have disadvantage on the attack roll. [...] When a creature can’t see you, you have advantage on attack rolls against it.

Detriment from heavy obscurity

Also note, any party members outside the cone that don't have darkvision also can't see each other, presenting some trade offs for using a bullseye lantern.

Achieve surprise

Assuming you are in an adventuring party, it's unlikely you could achieve surprise carrying a bullseye lantern, even if you and your party members weren't actually in the cone of light since

Any character or monster that doesn’t notice a threat is surprised at the start of the encounter.

It depends on whether the DM determines a beacon of light is a threat.

You can imagine a sort of comical scene where an enemy sees the light, but not the carrier of the lantern, or the party if they stay outside the cone emitted by the lantern.

Avoiding getting surprised

Keeping the entire party out of the lantern's cone of light may be a good strategy to avoid getting surprised, even from creatures with darkvision, at least leveling the playing field. In order for this to work, you and your party need to stay outside of the cone of light.

The beacon should prevent creatures from hiding within the bright light, but that is not an explicit rule. The hiding sidebar from Dexterity (Stealth) mentions

You can’t hide from a creature that can see you clearly[...]

Check with your DM

Xanathar's shows a 30' cone on a grid as

This shows a 30', 90 degree angle cone, but in your case, would be twice the length for bright light, and another 60' with dim light, illuminating a whopping 288 5' squares, 72 of which are bright, according to Pythagorus (1/2 x base x height in 5' units), assuming 2 dimensions.

What does this look like?

Using roll20, if you place a light in the square next to the player that emits 60' of bright light, 60' of dim light and make it directional with 90 degrees, which you'll need to rotate to "point" the lantern,

Here's the view from a creature with darkvision, just outside of the bright light.

And from the point of view of the player holding the lantern. Note, without darkvision, he cannot see his allies.

This is the view from one of the players in darkness that has darkvision.

Answer 3

I'm not aware of any official ruling on the topic, so you (or your DM) would have to fall back on common-sense reading.

If I point the bullseye lantern away from me, is my character illuminated in any way? Am I included in the cone of light, or am I outside of the cone, like when casting the Cone of Cold spell?

I think clearly you're outside the cone of light. That's the how the lamp works, assuming a perfectly assembled lamp that doesn't leak light in any direction other than out the shutter.

If I remain in darkness when using a Bullseye Lantern, then I can remain invisible to those without dark vision, while illuminating my enemies.

Darkness doesn't make you invisible in the first place. So it's not clear what you mean by "remain invisible". You can't "remain" something you aren't to start with.

If you are actually invisible, then whether using the lamp would terminate your invisibility or not depends on the source of the invisibility (which, as established, we already know isn't the darkness…might be a spell, or a cloak, or whatever). But generally, invisibility is, at worst, terminated by an attack, and using the lantern wouldn't normally be considered an attack, so if you had actual invisibility, the lantern shouldn't affect that, even as it would reveal your position.

Note that I'm assuming here that you're playing with the interpretation of the interaction of light sources and invisibility where light sources held by an invisible creature still emit light visible to others. There is no clear consensus on this, especially since Jeremy Crawford's tweets no longer are authoritative for rules interpretation. You could assume that invisibility prevents the lantern from being seen, but then it would also be of no use and irrelevant to the question you asked.

Now, all of the above said…

First, note that the description of the lantern doesn't even tell you the exact dimensions of the cone, except its length. Spot lights are generally modeled in computing as a zone of full brightness, shaped like a cone, with a larger cone around that where the light falls off, and then finally with complete darkness anywhere outside the larger cone.

Even using that idealized version of a lamp, you have to decide what the angles of those cones are, something not provided to us. So, make some assumptions. Say, the inner cone is 45 degrees and the outer is 90.

More relevant though is your environment. Take a very bright flashlight outside in the dark, and shine it straight up in the air. You won't be illuminated at all by the flashlight. On the other hand, if you shine it on the ground, then depending on what's actually on the ground you will be illuminated to some degree. Lighter colored surfaces will illuminate you more than dark surfaces, but in most cases there will always be some light that bounces back onto you.

So, are you in a small limestone cave when you do this? Then it is likely the light cast by the lantern will be reflected by many surfaces around you, illuminating you fairly well.

On the other hand, are you outside on a plain of black lava? If so, then little or no light is going to be redirected toward you, and you'll remain unilluminated. Though of course, if your opponent has a shiny shield and positions it to reflect the lantern's light back on you, you might wind up illuminated after all.

So the exact effect of the lantern is situationally dependent. If something happens where it matters how well anyone can see you, your DM will have to determine based on what's actually going on and where you actually are, how that all plays out.

Noting, of course, that merely using the lantern gives any other creature a clear indication of your position. Even if your body is coated in 100% light-absorbing black pigment, unless you are dangling the lantern from a pole well away from your body or something, it's not going to be hard to infer where an attack ought to be directed for a reasonable shot at hitting you.

If you are in fact completely light-absorbing, then I'd rule that you blend in with the complete darkness around you, rendering you effectively invisible, giving attacks against you disadvantage (and your own attacks advantage). The lantern in that case acts similarly to your footprints in sand exposing your location.

But otherwise, the more likely outcome would be something akin to applying the rules for cover, with a +2 or +5 bonus to AC, depending on just how much light has bounced back on you.

Answer 4

This answer is a rules as an interpretion of the scenario and how I would handle it. My answer is not a rules as written nor a rules as intended response. For clarity, my answer is from the point of view of the lantern holder so when I say YOU I mean the lantern holder, when I say attacker or enemy I mean NOT you, but those who would be attacking you.

Although you do not become invisible simply by being in the dark. If what you were aiming the bulleye lantern at wanted to attack you, all it would have as a reference is the point of light. Chances are really good you are holding the lantern out in front of you. However, everything behind the lantern would likely be black due to being bedazzled by the lantern's light.

If what was attacking you was to the side of the beam or cone of light, then you would likely be partially illuminated due to reflection of the light reflected back from the ambient dust in the air and surrounding objects that reflect the light even a little back at you. In this case, you wouldn't be "lit up", but you would be clear to see.

In the first case, I would this should be treated akin to or like half cover. Your cover isn't shielding you, but it IS making it harder to target you properly. A ranged attacker can aim for the lantern or just adjacent, but there is no guarantee you will be where they aimed. In the case of melee, it's somewhat the same, they know where you are likely to be, but you have the advantage of sight whilst they do not and you have an advantage to dodging. Either use disadvantage for the attacker, or the half cover rules of +2 AC and Dex Save.

In the second case, chances are YOU would be surprised by the attack because you are partially dazzled by what IS illuminated, and probably focused in that direction as well. In this case, I would definitely give your attacker Advantage to any relevant attack rolls.