D&D 5E Vision, light and ambush

[Charlaquin]

Looking for clarification on how to handle the following scenario:

• Party of four adventurers, fighter in the front carrying a torch (bright light in 20 feet radius, dim light in 20 feet radius)
• Party enters a dark room via an open archway (no door)
• Party is not actively looking for danger (no active Perception checks)
• Kobold (darkvision 60 ft) is in the room

Are the following assumptions correct?

1. The kobold can see the adventurers approaching (without making a check) because they are carrying a light source
2. The adventurers can't see the kobold at all as long as it stays outside the 40 foot light radius from the torch

So far so good.

3. The kobold can try to hide in the dim light of the torch (between 20 and 40 feet from the fighter, let's assume it's 30 feet away)

No. Once the kobold is within the dim light radius, the party can see it, and the guideline for stealth is “you can’t hide from a creature that can see you.” However, the kobold can hide if it remains in the darkness beyond the torchlight.

4. The kobold doesn't have a Stealth score, so uses its Dexterity bonus (+2) to hide

Basically, but for clarity of how the rules work, technically all creatures make a Dexterity check when they try to hide. Having the Stealth skill merely allows the creature to add their proficiency bonus to the Dexterity check. In the case of monster stat blocks, they do the math of adding those values together next to skills they are proficient in.

5. The kobold's Dexterity (Stealth) check is opposed by the passive Perception scores of the PCs

Not according to the scenario you set up. You said the party isn’t looking for danger. A passive check “represent(s) the average result for a task done repeatedly, such as searching for secret doors over and over again, or can be used when the DM wants to secretly determine whether the characters succeed at something without rolling dice, such as noticing a hidden monster.” Personally, I would rule that if the party is not continuously looking for signs of danger, then it isn’t appropriate for them to make a passive Wisdom (Stealth) check, and the kobold would succeed at its attempt to hide without a check.

6. The passive Perception score is penalized by -5 because of the dim light

Assuming the party had been watching for danger, then yes, their passive Wisdom (Perception) checks would be at -5 to notice anything in the dim light visually. They would also be unable to notice anything in the darkness visually, which again, is a precondition for the kobold to be able to hide.

7. Let's assume the fighter with the torch fails his passive Perception check, he is now surprised

I would argue that neither the fighter nor any of the rest of the party even got to make a passive Wisdom (Perception) check, which does seem like reasonable grounds to say they’re surprised at the start of combat,

8. Let's assume the kobold wins initiative and goes first
9. The kobold can now use its move (30 feet) to approach the fighter
10. After the first 10 feet of movement, the kobold enters the area of 20 feet bright illumination around the fighter, but does not need to make a new Stealth check
11. The kobold still counts as an "unseen attacker" and can attack the fighter with advantage on the attack roll
12. After making the first attack, the kobold has now given away his location (regardless of whether he hits or misses), and is no longer unseen

No. As soon as the kobold enters the dim light, it can be seen and is therefore no longer hidden from the party. Being surprised doesn’t prevent a character from seeing what’s in front of them. If the kobold wants to remain hidden, it would be more effective to remain in the darkness and use a ranged attack. That said, surprise is still incredibly useful, even if you aren’t hidden from your targets at the time when you attack them.

Items 10-12 are the crux of the question: Will the kobold be able to attack with advantage, or is he no longer considered "unseen" as soon as he steps into the bright light? If so, how would a darkness-dwelling creature ever be able to attack a torch-bearer with advantage?

Ranged attacks.

Bonus question: Assume two PCs in the front row, each carrying a bullseye lantern (casts bright light in a 60-foot cone and dim light for an additional 60 feet) at a slight angle from each other, so it covers a 180-degree half-circle in front of the party (and perhaps the same for the two PCs in the back).

Small nitpick, but the way a cone is defined in 5e (its width at a given point along its length is equal to that point’s distance from the point of origin) is actually only 1 radian, or 57.2958 degrees, so two bullseye lanterns angled this way would only cover a 2-radian, or 114.592 degree arc.

While monsters would still be able to surprise this party (by hiding in the dim light, thus giving a -5 to the passive Perception of the PCs), "normal" monsters with 30 feet of movement would not be able to (melee) attack on the first round of combat, because they would need to take the Dash action in order to close the distance to the PCs? Apart from obviously giving away your position to every creature in the dungeon (and problems with using shields and two-handed weapons at the same time as carrying lanterns), why wouldn't a party of PCs always be carrying as many bullseye lanterns as possible? I guess if the room had features such as columns, statues, furniture, etc the monsters could use these to hide behind and be closer than 30 feet regardless of the level of illumination?

Bullseye lanterns are pretty useful, for sure. Though since they only shed light in a cone instead of a sphere, a lot of players don’t really bother with them, since they leave you much more vulnerable to attacks from the flanks. As you say, enemies can hide behind cover, wait for the lantern bearers to pass, and then attack from behind while remaining unseen.

A good strategy for a party is to have bullseye lanterns in the front ranks and torches or hooded lanterns in the middle and back ranks.

 

[xoth.publishing]

Thanks everyone for the feedback. I understand that the rules are somewhat vague on purpose, and depends on DM fiat.

Going by the rules as written, and the feedback given, here are my key takeaways:

• You can't hide in dim light, you must hide in the darkness outside the torchlight (exceptions include the wood elf racial ability and the Skulker feat)
• Moving into the light makes you no longer unseen, so you do not get advantage on the attack roll (although the Hiding rules say that "under certain circumstances, the DM might allow you to stay hidden as you approach a creature that is distracted, allowing you to gain advantage on an attack roll before you are seen." so the question here is what kind of "distractions" would apply in the typical party-moves-into-next-dungeon-room scenario)
• You could fire ranged weapons from the darkness, and gain advantage on the (first) attack roll
• Regardless of lighting conditions, you could hide behind terrain (rubble, columns, etc) and thus get closer to your victim, although you still don't get advantage on the attack roll unless the victim is somehow "distracted" (how?)
• The primary benefit that you will get from hiding and ambushing is that you can surprise your victims (ie victims who are surprised will lose a round of actions)

 

[aco175]

I tend to have problems with the first part of your post saying that the party walks into a dungeon and is not looking for danger. You can argue that the players did not say they are looking for danger, but you can also say it is assumed in a dungeon. I could see if the PCs were in a tavern and maybe easier to say they are not on the lookout for danger. We have other threads on this before with things like drinking water throughout the day and not refilling your canteen or not cleaning your pots and pans so now you may get sick.

This also come down with parties developing 'standard door opening procedures', developed from clashes with the DM playing gotcha and the players becoming paranoid. Not my game but some like it.

I would tend to rule in the above situation that the party is surprised if they can not see the kobold and fail a perception roll. I would allow a roll entering the room even if they can not see everything, they may hear something or come up with a reason. I may even have them roll with disadvantage if they is a lot of debris or other factors like running water or something distracting them. The kobold runs into the light would still have surprise if the PCs failed Perception in the first place since something just rushes out of the darkness at you. I give the PCs would have weapons drawn in a dungeon (even if they did not actively say so) but would still think they are surprised.

Some may argue that adventurers are professionals and this is their job, so they should always get a chance, but I would point to the Perception check that gave them a chance and internal that it is just a kobold that the PCs should be able to handle. A bigger point is what is the kobold hiding that he would charge a party by himself or why he didn't hide or just run away.

 

[xoth.publishing]

I tend to have problems with the first part of your post saying that the party walks into a dungeon and is not looking for danger. You can argue that the players did not say they are looking for danger, but you can also say it is assumed in a dungeon.

To clarify, what I meant to say was that the party was assumed to be on "default alert" and therefore the default passive Perception checks would be used. I agree that some level of danger can always be assumed in a dungeon (as opposed to, for example, the marketplace in a sleepy village).

 

[Charlaquin]

Thanks everyone for the feedback. I understand that the rules are somewhat vague on purpose, and depends on DM fiat.

Going by the rules as written, and the feedback given, here are my key takeaways:

• You can't hide in dim light, you must hide in the darkness outside the torchlight (exceptions include the wood elf racial ability and the Skulker feat)
• Moving into the light makes you no longer unseen, so you do not get advantage on the attack roll (although the Hiding rules say that "under certain circumstances, the DM might allow you to stay hidden as you approach a creature that is distracted, allowing you to gain advantage on an attack roll before you are seen." so the question here is what kind of "distractions" would apply in the typical party-moves-into-next-dungeon-room scenario)
• You could fire ranged weapons from the darkness, and gain advantage on the (first) attack roll
• Regardless of lighting conditions, you could hide behind terrain (rubble, columns, etc) and thus get closer to your victim, although you still don't get advantage on the attack roll unless the victim is somehow "distracted" (how?)
• The primary benefit that you will get from hiding and ambushing is that you can surprise your victims (ie victims who are surprised will lose a round of actions)

By my reading, the rule about being able to approach a distracted creature is there to make it possible to sneak up on an unsuspecting opponent before combat starts. In combat, creatures are assumed to be alert to threats from all directions (unless you’re using the optional facing rules from the DMG). If this applied outside of combat, melee sneak attacks would be impossible against conscious creatures, unless they’re blinded or something.

It could be argued that since the party in your example is not searching for danger, they are distracted enough for the kobold to remain hidden while approaching. That’s your call to make as the DM, though it’s probably not a ruling I would make personally. I would only rule that the kobold can remain hidden while approaching a character that is engaged in some activity other than looking out for danger. For example, if they’re searching for secret doors, examining some runes on the wall, attempting to pick a lock, casting a ritual spell, etc. Of course, smart players will likely have some party members keep watch while others do these kinds of distracting activities, which would make it much more difficult for the would-be ambusher to pull this stunt off.

 

[Charlaquin]

To clarify, what I meant to say was that the party was assumed to be on "default alert" and therefore the default passive Perception checks would be used. I agree that some level of danger can always be assumed in a dungeon (as opposed to, for example, the marketplace in a sleepy village).

So, an important part of the exploration rules that often gets overlooked is that you can only be engaged in one activity at a time. So, while I think it’s reasonable to assume that party members are keeping alert for danger and therefore contributing their passive Wisdom (Perception), any characters who are engaged in other activities should not do so. Basically, same guidelines that would constitute a sufficient distraction to allow a hidden opponent to remain hidden on approach. If you’re making a map (which someone should DEFINITELY be doing in a dungeon!), searching for secret doors, that kind of thing, you are too distracted to contribute your passive Wisdom (Perception) and vulnerable to being snuck up on.

 

[Oofta]

Thanks everyone for the feedback. I understand that the rules are somewhat vague on purpose, and depends on DM fiat.

Going by the rules as written, and the feedback given, here are my key takeaways:

• You can't hide in dim light, you must hide in the darkness outside the torchlight (exceptions include the wood elf racial ability and the Skulker feat)
• Moving into the light makes you no longer unseen, so you do not get advantage on the attack roll (although the Hiding rules say that "under certain circumstances, the DM might allow you to stay hidden as you approach a creature that is distracted, allowing you to gain advantage on an attack roll before you are seen." so the question here is what kind of "distractions" would apply in the typical party-moves-into-next-dungeon-room scenario)
• You could fire ranged weapons from the darkness, and gain advantage on the (first) attack roll
• Regardless of lighting conditions, you could hide behind terrain (rubble, columns, etc) and thus get closer to your victim, although you still don't get advantage on the attack roll unless the victim is somehow "distracted" (how?)
• The primary benefit that you will get from hiding and ambushing is that you can surprise your victims (ie victims who are surprised will lose a round of actions)

If you are unseen when you attack you have advantage. Attacking a creature you can't see is always at disadvantage even if you know it's location. So the kobolds could make ranged attacks from the darkness 120 feet away and have advantage, which is cancelled out by the disadvantage for long range.

 

[DND_Reborn]

• You can't hide in dim light, you must hide in the darkness outside the torchlight (exceptions include the wood elf racial ability and the Skulker feat)
• Moving into the light makes you no longer unseen, so you do not get advantage on the attack roll (although the Hiding rules say that "under certain circumstances, the DM might allow you to stay hidden as you approach a creature that is distracted, allowing you to gain advantage on an attack roll before you are seen." so the question here is what kind of "distractions" would apply in the typical party-moves-into-next-dungeon-room scenario)
• You could fire ranged weapons from the darkness, and gain advantage on the (first) attack roll
• Regardless of lighting conditions, you could hide behind terrain (rubble, columns, etc) and thus get closer to your victim, although you still don't get advantage on the attack roll unless the victim is somehow "distracted" (how?)
• The primary benefit that you will get from hiding and ambushing is that you can surprise your victims (ie victims who are surprised will lose a round of actions)

Well, by the books you don't need to be in darkness to hide, you simply need to be unseen when you attempt to Hide if you do so while in dim light or light obscurement. In fact, Hiding in darkness is pointless (unless it is just to be quiet of course) since you are automatically unseen. "Shadows" are considered dim light, and people hide in shadows all the time. Now, if someone watches you doing it, they are going to see you trying to Hide and know where you are.

There is a reason why there is disadvantage on perception checks in dim light. You aren't "clearly seen".

As to the types of distractions, it could be a number of things. One foe might reveal themselves, making noise, etc. to allow others to attack while the party is distracted. They could toss a rock or something, making noise to put there attention "over there"!

You can fire a ranged weapon from any "Hidden" position, it doesn't need to be from darkness. If you fire from darkness, you are automatically "unseen" and have advantage--that is totally correct.

No, you aren't really "Hiding" behind terrain. If the observer sees you moving there, you simply have cover (total or less depending on the size of the object). They are aware of your location, even if they can't target you due to losing light of sight.

Correct, it is all about surprise. Remember that a creature cannot even take reactions during a surprise round until its turn comes up. Although the surprised creature can't act on its turn, from that point on it can still take reactions normally.

 

[Hriston]

Are the following assumptions correct?

1. Yes
2. Well, I'd say they can't see the kobold clearly, which is good enough for it to try to hide.
3. No
4. Yes, hiding is a Dexterity check. You add your proficiency bonus if you're proficient in Stealth.
5. Yes, as long as the PCs aren't navigating, tracking, foraging, or drawing a map
6. No, see #3.
7. Yes, he is surprised when/if combat begins.
8. Okay?
9. Yes
10. As soon as the kobold enters the radius of the torchlight (40 feet), conditions are no longer appropriate for hiding, and it is noticed by the fighter and anyone else from whom it was formerly hidden.
11. No
12. No, the kobold was no longer unseen as soon as it entered the radius of the torchlight.

Items 10-12 are the crux of the question: Will the kobold be able to attack with advantage, or is he no longer considered "unseen" as soon as he steps into the bright light?

The kobold is no longer unseen as soon as it steps into the dim light.

If so, how would a darkness-dwelling creature ever be able to attack a torch-bearer with advantage?

They could stay in the darkness and make a ranged attack.

Bonus question: Assume two PCs in the front row, each carrying a bullseye lantern (casts bright light in a 60-foot cone and dim light for an additional 60 feet) at a slight angle from each other, so it covers a 180-degree half-circle in front of the party (and perhaps the same for the two PCs in the back). While monsters would still be able to surprise this party (by hiding in the dim light, thus giving a -5 to the passive Perception of the PCs), "normal" monsters with 30 feet of movement would not be able to (melee) attack on the first round of combat, because they would need to take the Dash action in order to close the distance to the PCs? Apart from obviously giving away your position to every creature in the dungeon (and problems with using shields and two-handed weapons at the same time as carrying lanterns), why wouldn't a party of PCs always be carrying as many bullseye lanterns as possible? I guess if the room had features such as columns, statues, furniture, etc the monsters could use these to hide behind and be closer than 30 feet regardless of the level of illumination?

There are a lot of variables in this question, but my main point of disagreement is with the notion that creatures can hide in an area of dim light. As others have said, this would require a special feature.

 

[Laurefindel]

Indeed, there is a case to be made about dim light not allowing something to be clearly seen.

if dim light allowed things to be seen clearly, it wouldn’t impose disadvantage on Wisdom (perception) checks. Can something be seen clearly in lightly obscured area.

ah, semantics...