D&D 5E Vision, light and ambush

[xoth.publishing]

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
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)
4. The kobold doesn't have a Stealth score, so uses its Dexterity bonus (+2) to hide
5. The kobold's Dexterity (Stealth) check is opposed by the passive Perception scores of the PCs
6. The passive Perception score is penalized by -5 because of the dim light
7. Let's assume the fighter with the torch fails his passive Perception check, he is now surprised
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

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?

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?

 

[Ovinomancer]

Couple of things.

First, while it is the GM's call, dim light alone is usually insufficient to hide, as you can usually see in dim light.

Second, to answer your crux question, no, the kobold should not keep hidden attacker after moving from their hiding spot. While this is another GM call, the logic isn't that the kobold gets unseen attacker set for their whole turn if they start unseen, but rather gets unseen attacker only while, you kniw, actually unseen.

 

[NotAYakk]

To be hidden you typically need more than dim light. You need something to hide behind.

By default, hide ends when you are out in the open. You can peak around vision blocking cover and make an attack while hidden, but you cannot walk up to someone.

Add some rubble for the Kobold to hide behind and your example works. Once the Kobold runs into the light, if there is terrain to hide behind it could stay hidden, if not no it is seen.

 

[iserith]

Also, there is no such thing as an "active Perception check" in D&D 5e and in this situation, provided the players have established that their characters are focused on watching for danger while traveling the dungeon and are in the position to do so, the DM uses passive Perception to determine whether the PCs are surprised when combat breaks out and whether the kobolds are hidden (not clearly seen and unheard).

 

[Shiroiken]

1. Correct
2. Correct
3. Incorrect. You need heavy obscurement to hide without a special ability, so dim light isn't sufficient.
4. Correct
5. Correct
6. It's at -5 for the darkness, because the dim light is irrelevant.
7. Sort of. You check the entire party, not just individual PCs, at the point of rolling initiative.
8. Okay
9. Okay
10. Correct... sort of. You don't need to make multiple checks when moving while invisible, but see #11
11. Incorrect. Once the kobold leaves heavy obscurement, they are visible regardless of stealth checks. I have allowed it during moments of distraction, either mid-combat or in a busy street, but that parts entirely a DM judgement.
12. Correct
13. 
    
14. 
    

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?

with 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?

Light is a tricky issue for groups. Darkvision makes light less important for some characters, and except for a handful of characters, PCs tend to keep their hands full. Our group pretty much always uses the Light spell because it allows everyone to have a free hand. In our Avernus campaign, our human wizard also carries a torch, since he has a free hand... and had a bad experience once when the Light spell moved around a corner.

 

[Oofta]

For better or worse, the rules on stealth and hiding are left vague on purpose so that the DM can do what makes sense to them. In other words, don't expect a consensus.

Because right off the bat, I disagree with the other posters. Don't worry, it's not the first time and it certainly won't be the last.

With that out of the way, anybody running around with a torch is going to be from very far away. Like a literal mile away if there's nothing obscuring the light. There's nothing in the books about it, just common sense.

Okay on to the rules from chapter 7 of the PHB.

HIDING​

​

The DM decides when circumstances are appropriate for hiding. When you try to hide, make a Dexterity (Stealth) check. Until you are discovered or you stop hiding, that check's total is contested by the Wisdom (Perception) check of any creature that actively searches for signs of your presence.​

​

You can't hide from a creature that can see you clearly, and you give away your position if you make noise, such as shouting a warning or knocking over a vase. An invisible creature can always try to hide. Signs of its passage might still be noticed, and it does have to stay quiet.​

Also from the PHB chapter 8 on Vision and Lighting

A given area might be lightly or heavily obscured. In a lightly obscured area, such as dim light, patchy fog, or moderate foliage, creatures have disadvantage on Wisdom (Perception) checks that rely on sight. ​

So I highlighted a couple of key things there, "The DM decides" and "can see you clearly". We know that dim light is considered lightly obscured. You need to decide if that means the kobold could be clearly seen. Yeah, I know it's kind of a cop out, but it really depends on the kind of game you want to run.

So if you want to be on the conservative side stay outside of the edge of the light. You have disadvantage with your sling but that will be countered by the advantage of being an unseen attacker. Again, whether the kobold gives away their position is up to you, I'd give the PCs general direction. So depending on how much range the kobold has, I'd consider pegging them from a distance and then retreating. Rinse and repeat. Just be careful to not make it too frustrating - but you know your group and I don't.

Oh, and I wouldn't require a stealth check for the kobolds in the darkness unless they're being noisy. Again, opinions will vary and I'm sure I'll be told I'm wrong.

So what about sneaking in dim light? Personally I'd consider allowing it. Probably with disadvantage, but the PC's passive perception is also at disadvantage so -5. Once they attack (with advantage if hidden) I'd say they've revealed themselves.

So there you have it, how I'd run it. Run it the way you think will be reasonably fair, try to be consistent and remember the goals is to have fun. There are going to be a lot of situations where you just have to decide how you're going to run things.

Good luck and have fun!

 

[jgsugden]

1. The kobold can see the adventurers approaching (without making a check) because they are carrying a light source (Yes)
2. The adventurers can't see the kobold at all as long as it stays outside the 40 foot light radius from the torch (assuming they do not have darkvision or the kobold is outside the range of darkvision - yes_)
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) (maybe - up to the DM. The DM decides when circumstances are appropriate for hiding. The guidance is that you lose your hide 'condition' if the target can see you clearly. It is up to the DM to determine if you can be "seen clearly". Most DMs seem to require heavy obscurement to hide as there are specific racial abilities that allow it in light obscurement which would be irrelevant otherwise. In my campaigns, you can hide (if silent) in heavy obscurement always, and you can hide in light obscurement when the cirucmstances support it in my judgement)
4. The kobold doesn't have a Stealth score, so uses its Dexterity bonus (+2) to hide (yes)
5. The kobold's Dexterity (Stealth) check is opposed by the passive Perception scores of the PCs (yes, unless the DM rules otherwise. For example, I rule that characters are using their perception actively and give them a roll if PCs are not double moving or taking other actions).
6. The passive Perception score is penalized by -5 because of the dim light (it would be if relevant - perhaps if the kobold approaches from behind a concealing obstacle)
7. Let's assume the fighter with the torch fails his passive Perception check, he is now surprised (whether there is surprise or not is entirely up to the DM)
8. Let's assume the kobold wins initiative and goes first (no … ok, you talked me into it)
9. The kobold can now use its move (30 feet) to approach the fighter (yes)
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 (generally no - the kobold's hide 'condition' ends at the moment it can be seen clearly, which it does when it enters the bright light. However, if the DM rules the PCs are distracted, the kobold might still be able to approach and get advantage. It is a DM call.)
11. The kobold still counts as an "unseen attacker" and can attack the fighter with advantage on the attack roll (see above)
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 (generally yes, although the DM might rule that a missed attack and a distracted PC might not give away the location. It is up to the DM.

In the end, the first sentence of the Hiding rules is the key language. The DM decides when circumstances are appropriate for hiding. They had the opportunity to make very complex and detailed hiding rules or to give a little general guidance and tell the DM to make judgment calls. They chose the second approach to avoid rules with nuances that resulted in chaos and frustration. They discussed their approach when the rules were released.

Here are my hiding guidelines for players:

• As long as you are being quiet (and the target has no relevant advanced sense of smell, etc..), you can always try to hide when heavily obscured or totally concealed.
• Unless the target is either not using an action to do something or is using their action to do perception checks, you use the creature's passive perception.
• As long as you are being quiet, you can hide in light obscurement if the target is distracted (using their action for something other than perception) or you have an ability that allows it. Note that perception checks relying on sight are at disadvantage in light obscurement, meaning generally that passive perception is at -5.
• If you successfully hide, you remain hidden until either 1.) the target sees you clearly (bright light), smells you, feels you, or hears you; or 2.) the target sees you via light obscurement and is not distracted.
• You can move quietly at normal speed if hidden without requiring a new stealth role unless there is a change in your environment that calls for it (stepping into broken glass, etc...)
• If a creature has darkvision, and no dim light support, you are lightly obscured from it. That means that if you can distract the enemy (or it distracts itself), you can approach it while hiding.
• If a creature is distracted and has the aid of bright light (or otherwise could 'see you clearly', such as when it has blindsight), you can attempt to approach it while staying hidden by making an additional stealth check. If you move more than half your speed while approaching, this role is made at disadvantage. This would be an additional role made at that time, in addition to the one you made to enter the 'hidden condition' when you could not be perceived so easily)
• If you are hidden from a creature and lose the hidden 'condition' due to lack of concealment, etc... you must use a hide action to restore the hidden condition versus that creature.

 

[DND_Reborn]

Welcome to Stealth in 5E. Good luck!

The others have hit on key points, but with only a couple key exceptions there are no "hard and fast" rules for such things in 5E (like much of the game).

Mostly it comes down to judgement calls. I was showing one of our players last night the ins and outs of DMing, and lighting, stealth, perception (including passive), advantage and disadvantage, sleeping targets, prone, surprise, and more all came up. So, the main point is come up with a way your entire table decides works well for you and stick with it. You might revise things at some point, but as long as everyone is having fun, don't sweat it.

I will point out one thing. You don't need to be heavily obscured to take the Hide action, you need to be unseen when you do it. If someone is looking right at you, you can't attempt to Hide in dim light/ light obscurement, such as shadows, patchy fog, moderate foliage, etc. You also do not need something to Hide behind. The shadows created by dim light can be sufficient if the DM rules they are. Now, certain features will allow someone under direction observation to attempt to Hide while being lightly obscured. Those are exceptions, not the rule.

If you are heavily obscured due to darkness, dense fog, etc. such conditions "block vision entirely". Creatures effectively are blind to you and perception checks fail automatically as they simply cannot see you.

 

[xoth.publishing]

Also, there is no such thing as an "active Perception check" in D&D 5e

It's a matter of definition, I guess. From the rules on Hiding:

"When you try to hide, make a Dexterity (Stealth) check. Until you are discovered or you stop hiding, that check's total is contested by the Wisdom (Perception) check of any creature that actively searches for signs of your presence." (emphasis mine)

One of the actions you can take in combat is Search, which is basically (an active) Perception check.

That said, the surprise rules are clear that passive Perception should be used: "... the GM compares the Dexterity (Stealth) checks of anyone hiding with the passive Wisdom (Perception) score of each creature on the opposing side. Any character or monster that doesn't notice a threat is surprised at the start of the encounter."

 

[iserith]

It's a matter of definition, I guess. From the rules on Hiding:

"When you try to hide, make a Dexterity (Stealth) check. Until you are discovered or you stop hiding, that check's total is contested by the Wisdom (Perception) check of any creature that actively searches for signs of your presence." (emphasis mine)

One of the actions you can take in combat is Search, which is basically (an active) Perception check.

That said, the surprise rules are clear that passive Perception should be used: "... the GM compares the Dexterity (Stealth) checks of anyone hiding with the passive Wisdom (Perception) score of each creature on the opposing side. Any character or monster that doesn't notice a threat is surprised at the start of the encounter."

The key distinction is that there are ability checks of which passive checks are a subset. "Passive" also means there is no rolling, not that the characters are not active. Passive checks come into play generally when the characters are performing a task repeatedly over time (e.g. keeping watch for danger while traveling which is what the characters in your example are doing) or when the DM wants there to be a secret check for some reason. Thus there are no "active checks" in D&D 5e. A player can choose to take the Search action when in combat, but this may or may not come with an ability check, as determined by the DM.

As for your bolded part, it's important to remember that a check is not an action, nor an action a check. These things are separate and distinct. An action is a task that the character performs in the setting; a check is a mechanic outside the context of the setting which is used by the DM to determine the result of the adventurer's task when that task has an uncertain outcome and a meaningful consequence for failure.