How perceptive are trancing elves?

Question

The description of Elves' Trance racial trait says (emphasis mine):

Elves don’t need to sleep. Instead, they meditate deeply, remaining semiconscious, for 4 hours a day. (The Common word for such meditation is “trance.”) While meditating, you can dream after a fashion; such dreams are actually mental exercises that have become reflexive through years of practice. After resting in this way, you gain the same benefit that a human does from 8 hours of sleep.

The bold words seem to imply that even when an elf is in a trance he can make perception checks (possibly at a disadvantage), because they are semiconscious instead of unconscious.

Is that true and is that different than the way other races are when they sleep?

Answer 1

Sleeping is treated as being unconscious. Thus if an elf maintains consciousness throughout their trance, they are fully aware.

The big difference here is that the elf maintains consciousness. We do not at this time, have rules for what perception is like when a PC is sleeping (considering the use of unconscious, I'd guess it's automatic failure), so we can't necessarily determine what effect the semi-conscious meditation has on perception checks.

I'd say it's safe to assume that an elf can make perception checks (though generally for this kind of thing, passive is used), as normal with no penalty while meditating.

Answer 2

I've been allowing tranced elves to "come awake" instantly but have not been allowing them to consider a trance state the same as a PC (fully awake) on watch. Disadvantage on perception checks (or a minus 5 on passive perc) is a good way to account for a diminished, but not absent awareness of the surroundings. Thus an all elf party couldn't all go into trance together and expect the same level of vigilance as if one was on watch, but a spell like Alarm (or a loud noise like kicking down a door) would immediately let them come awake and into action.

Since there aren't (to my knowledge) any rules for someone to wake up, I usually require a sleeping character to take a "wake up" action (after a surprise round if that happens) before they can take normal actions. A tranced elf would not need to take such an action.

Considering a sleeping character to be unconscious is a pretty stiff penalty (attacks against it have adv, and a hit is a crit). Maybe consider them incapacitated (can't take actions or reactions) instead?

Answer 3

Jeremy Crawford gave a now unofficial ruling in 2017 via Twitter:

Trance doesn't suspend an elf's passive Perception. A DM could treat the elf as distracted and impose disadvantage.

Answer 4

The fact that it is different than real sleep isn't really contested much. There have been comments that they are supposed to be great for mid-shift guards at the very least because of trance. The hard part is how to adjudicate it.

I would use the Sleep spell as a baseline for sleeping characters and make them unconscious. Consider their passive perception as -5 (for disadvantage) when it comes to noticing what's going on and waking up. This means a very low wisdom character has a chance to sleep through a fight outside their tent. (Likely a DC 5 as a very simple task).

Trance, on the other hand, flat out states that it is different from sleep in the description. It is a meditation state, not a true sleep, and only has to be maintained for four hours. I would say that this also gives disadvantage as their focus is shifted internally, but this would be easily negated by the generally high perception that elves have. They would hear combat and normal noise regardless, but wouldn't likely hear an assassin.

All this said, the duration is the real prize. Elves don't need a full night's sleep to get their rest, so they can be alert for half of a long rest. During this time frame, they are not suffering from any penalties to their perception. Two elves can cover an entire watch with no worries at all about being asleep. This combined with their natural alertness makes it hard to ambush a group with at least 2 elves in it. (And fairly difficult to ambush them even if it's only 1.)

Answer 5

It's up to the DM, but less perceptive than usually

The DM is to set difficulty score and appropriate modifiers for making ability checks.

It would be safe to assume that a character who is "semiconscious" or "in a trance" has a harder time perceiving anything.

It should also be noted that usually when people meditate they close their eyes. An Elf who is meditating probably can't see anything so they can't benefit from any kind of sight (eg normal sight, Darkvision) or make checks that rely on sight (eg detecting Hidden foes).

For example what would be appropriate DCs for a meditating Elf to detect various things:

• Someone shaking them: DC 0, it wakes them up.
• A pinch: DC 10, even a sleeping can feel a pinch, but it isn't certain.
• Someone calling out to them by name: DC 15, most people respond to their name, it could well break them out of their trance.
• A noise nearby: DC 20, without sight normal noises may be tricky to detect.
• Someone waving their hand in front of the Elf's face: DC 25, not normally perceptible.
• A foe sneaking up: advantage to Stealth check, disadvantage to passive perception. Definitely a lot easier than sneaking up on an alert and conscious creature!

Answer 6

If you use the rules on Sleep in Xanathar's Guide to Everything

From XGtE "Sleep" (p.77):

When a creature sleeps, it is subjected to the unconscious condition.

Normally, a character subjected to the unconscious condition:

is unaware of its surroundings

However, Xanathar's also says (ibid)

A sudden loud noise — such as yelling, thunder, or a ringing bell — also awakens someone that is sleeping naturally.
Whispers don’t disturb sleep, unless a sleeper’s passive Wisdom (Perception) score is 20 or higher and the whispers are within 10 feet of the sleeper. Speech at a normal volume awakens a sleeper if the environment is otherwise silent (no wind, birdsong, crickets, street sounds, or the like) and the sleeper has a passive Wisdom (Perception) score of 15 or higher.

Thus, even though Xanathar's says that sleeping characters are unconscious, it also says (specific over general) that unlike other unconscious creatures, naturally sleeping characters are able to Perceive their surroundings and respond to sounds.

A trancing character, by definition, is not sleeping. Instead, they are meditating deeply. The natural English usage of meditation (and semiconscious) implies that they may be less aware of their surroundings than someone who is fully conscious, but that they are still more aware of their surroundings than someone who is asleep. Thus, a trancing elf should have a better chance to Perceive things than someone who is sleeping.

Advantage on a roll is the standard way to show that the situation is favorable for the person making a check; when no dice are rolled, as in a Passive check, favor is applied as a +5 bonus. A +5 bonus on a Passive check is equivalent to a -5 on the DC of the task and easier to compare.

Thus, for a trancing elf:

A sudden loud noise — such as yelling, thunder, or a ringing bell — will bring them out of their trance.
They will notice whispers if their passive Wisdom (Perception) score is 15 or higher and the whispers are within 10 feet.
Speech at a normal volume will also be noted if the environment is otherwise silent (no wind, birdsong, crickets, street sounds, or the like) and the trancer has a passive Wisdom (Perception) score of 10 or higher.

If you use the core rules only

Without Xanathar's, a normally-sleeping character does not have the unconscious state. Rather, they can be treated in certain situations as unconscious and others not, as the DM is told to apply the condition intuitively.

Thus, to resolve the OP's question, we now have to consider four states:

Conscious / Awake: the default condition with no penalties to Perception
Semiconscious / Trance: Perception to be determined
Lacking Consciousness / Normal Sleep: Perception treated by the DM intuitively
Unconscious: No Perception or awareness of surrounding conditions

If it is not immediately obvious that "semiconscious" should be closer to "conscious" than "lacking consciousness" is, recall that elves don't sleep, and instead they deeply meditate. The natural English usage of these words indicates that meditation is between consciousness and sleep.

Thus, we have two states to adjudicate between "no Perception" and "full Perception". We are told that the lower state should have Perception applied intuitively, and by natural language we know that the higher state will be more perceptive. This is as far as RAW can get us. Personally, I would simply default to Xanathar's rules on sleep for the sleeping state, but in the absence of these DM's are free to intuit as they will.