An elf receives the benefits of a long rest in 4 hours while using the "Trance" trait.
According to the 2017 update to the Sage Advice Compendium:
Q: Does the Trance trait allow an elf to finish a long rest in 4
A: If an elf meditates during a long rest (as described in the
Trance trait), the elf finishes the rest after only 4 hours. A
The spell enables relatively secure resting in dangerous places
You are correct that, on the whole this spell enables the party to rest securely knowing that they will not be murdered by the most common dungeon dangers while they sleep. They are safe from spells, creatures and objects that may try to encroach into their safety bubble.
Creatures can even fire ...
Although @aslum's and @J. A. Streich's answers talk about not being able to take Long Rests as frequently as the Wizard would like, no-one has mentioned that this is explicitly stated in the PHB page 186 under the definition of a long rest:
A character can’t benefit from more than one long rest
in a 24-hour period, and a character must have at least
The answers provided by Niel B and CaM are good (and both have my upvotes), but I want to emphasise another aspect of this, based on my own experience with running this adventure (although this exact thing didn't happen to me; the first long rest was some time after this):
Level 1 characters are weak as hell, and this first dungeon is quite difficult for ...
Yes, right up to the point where the goblins go fetch their shaman to cast Dispel Magic and fill the adventurers full of arrows.
The downside of your scenario is it hands all the strategic initiative to everyone outside the hut.
You will not receive any benefits of a long rest
This includes Hit Die refresh, Hit Point recovery, spell slots, abilities that refresh on a long rest, etc.
Basically, while you won't suffer the negative effects of skipping a long rest, you also don't enjoy any of the benefits of having taken one.
A party of 3 can finish a long rest in 10 hours
Lets say we have 3 characters, Aberforth, Barte, and Caius. During the first 2 hours, Aberforth can keep watch while the others sleep. Then during hours 3 and 4, Barte can be awoken to take watch, while Aberforth goes to sleep. Caius continues to rest until hour 5 and 6 when he is awoken for his watch. Barte ...
A few folks have mentioned to me that Mike Mearls has stated elsewhere that it's an oversight in the text, and the intent is that a level 1 character should recover 1 hit die. Seems likely errata-fodder.
@MrMattFree : Hit dice question! Basic rules say you get half your HD back at a long rest but doesn't say round up. What does a 1st lvl do?
@mikemearls : ...
Yes, you can do this
That's how it goes. Spell slots are regained at the end of a long rest, and there's no rule forbidding spellcasting during a long rest.
It's effective and somewhat cheesy, but not as broken as it might sound at first. To cast that spell before ending the rest, you need to save up a slot for it. If you intend to do this constantly, you ...
A long rest is interrupted by giving up on it
The text is ambiguous, but 1 hour is meant to apply to the whole period of strenuous activity, while the list is there to define what types of activities could make up that strenuous activity period. The intention is that the rest has to be started over not just for any interruption, but for those unusual times ...
The First Step Is Admitting You Have a Problem
Have you tried talking to your players about this playstyle? Why are they sticking with this approach? Before you start punishing them for not playing the way you expect them to, make sure this behavior isn't a symptom of a deeper problem.
Do they just enjoy unloading on every foe they see? This can indicate ...
I wrote my original answer in April 2015. More than 2 years later, the rules changed. While I am annoyed, I actually prefer the new rules as they sidestep the issue and just make sense.
To summarize: Now a long rest means 8 hours without exertion, of which 6 must be spent sleeping. And a completed 4-hour elvish trance explicitly counts as a long rest.
You have a balanced party. What they want makes sense.
The wizard is pretty cautious... because they are a wizard and are squishy.
The druid's player likes doing things that would be in character even if they aren't completely optimal, and likes the feeling of danger... because they are a cool Druid, and there is depth there. Right.
We also have a ...
A stabilized elf can finish a long rest in 1d4+4 hours.
The rules for “Stabilizing a Creature” state (emphasis mine):
A stable creature doesn't make death saving throws, even though it has 0 hit points, but it does remain unconscious. The creature stops being stable, and must start making death saving throws again, if it takes any damage. A stable creature ...
No, short rests and long rests are mutually exclusive.
The PHB has the following to say about long rests:
If the rest is interrupted by a period of strenuous activity - at least 1 hour of walking, fighting, casting spells, or similar adventuring activity - the characters must begin the rest again to gain any benefit from it.
From this we can infer that ...
No negative effects
Including the details on the Elven Trance feature here:
Trance: Elves do not need to sleep. Instead, they meditate deeply 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. ...
If a Wraith reduces your maximum HP to zero, you die
The explanation you've been given seems to be a little mixed up - it's not that necrotic damage inherently cannot be healed, but that the Wraith's attack deals necrotic damage and also has a secondary effect which can reduce your HP maximum until your next long rest:
Life Drain. Melee Weapon Attack: +6 to ...
Frame challenge: don’t let them benefit from a long rest at all.
The rules for a long rest say:
A long rest is a period of extended downtime, at least 8 hours long, during which a character sleeps for at least 6 hours and performs no more than 2 hours of light activity, such as reading, talking, eating, or standing watch. If the rest is interrupted by a ...
Yes, you can maintain concentration
Concentration is ended by (PH chapter 10):
Casting another spell that requires concentration.
Being incapacitated or killed.
Or "The DM might also decide that certain environmental phenomena..."
As a short rest does not require casting any spells, cause damage, inflict the incapacitated condition, kill ...
Resources are regained at the end of a long rest.
The barbarian's rage class feature states:
you must finish a long rest before you can rage again.
Spellcaster's spell slot section states:
You regain all expended spell slots when you finish a long rest.
For hit points and hit die:
At the end of a long rest, a character regains all lost hit points. The ...
Catnap is a shorter short rest
If a target remain unconscious for [ten minutes], that target gets the benefit of a short rest ...
This is supposed to be a helpful spell not an offensive one. You use it on allies to give them the benefit of a short rest (which normally takes at least an hour) in only 10 minutes.
Short rests have many useful effects like ...
Yes, it is possible (depending on your circumstances and DM)
Nothing in the rules prevents this
There is nothing in the rules for resting that prescribes the environment that you can rest in. There are only certain things that interrupt rest according to the rules:
If the rest is interrupted by a period of strenuous activity - at least 1 hour of walking, ...
Simplest solution: Switch from 5E short rests (an hour each, too long to occur reliably between most encounters) to something closer to 4E short rests (5 minutes, essentially automatic outside of densely packed back-to-back encounters). You don't have to skip straight to 5 minutes, but making it short enough that you'd believably spend that much time on ...
Almost definitely nothing.
The rest variant you have described, where a short rest is 8 hours and a long rest is 1 week, is exactly as described in in the Dungeon Master's Guide on page 267 in a section on Rest Variants.
The designers suggest this option for "gritty realism" and do not provide any warnings about what this might break or imbalance, and ...
Resource-less can be a mistake or by design.
I'm DMing a campaign where the PCs start without any gear, broken and chained to the wall, and they do not get any chance to rest before finishing the first chapter. Harsh, but that was the design.
In your case, it may be that the area you are in was supposed to be something you run through, without exploring or ...
Yes, warlock spell slots return on a short rest
In fact, warlock spell slots return on a short or long rest, not just short rests, as detailed on PHB page 107 under the Spell Slots section of the Warlock's Pact Magic feature:
[...] You regain all expended slots when you finish a short or long
I'll step through each of the classes individually, but first the broad strokes:
[Most] Spellcasters will fare much better than everyone else
The main check on the power of a Spellcaster is their limited resources. If a Level 9 character uses a 5th Level Spell Slot, that's it: that's the only fifth level spell they'll get for the whole day. Wizards and Land ...
It's first worth mentioning that the Sage Advice you cite is now obsolete; errata have been released which contain a correction so that long rest does now require sleep as a general rule:
A long rest is a period
of extended downtime, at least 8 hours
long, during which a character sleeps for
at least 6 hours and performs no more
than 2 hours of light ...
This is not normal, because the DM has either violated the rules or instituted modified rules without telling you.
From the interaction you described with the DM, it sounds to me like your DM believes you are playing the rules as written, even though the rules as written clearly state that you can resume your long rest as long as the strenuous interruption ...