Resting in 5e

Resting in 5e is a much bigger topic than I expected when I started to brainstorm about this post.  Things I often hear is that clerics or healing classes aren't really need anymore because of the short rest, and that can be true, but it's a huge misstatement of the game.  The obvious glaring example is that if a party attempts a long or short rest in a dungeon, they are going to have to depend on other skills and abilities to not be ambushed and disrupt the rest.  This is of course where the Evil DM comes in, because usually players need to rest once they have used spell slots and have taken a beating, usually in a combat area.  Taking that away from them can easily result in a deadly session.

I have found there is a real art to disrupting rests.  It should never be expected, and it should always fit into the narrative.  Are the monsters or threats capable of actively looking for the party?  Are there monsters or threats further down that would stumble upon the party?  Role playing the monsters is super important here, because monsters and threats should be believable as often as possible in game.  Also, heavy handed disruptions make the game a drag if you use them too often.  

I personally like the idea of the short rest, because a long rest in a heavy combat area is unlikely.  Sure there are spells and items that can assist, but just as a general statement, a party isn't usually going to be setting up a camp inside of a dungeon.  Short rests however, can be done, and more than once (they have to be spaced, obviously).  Also, if you are a newer DM for 5e, keep in mind that the RAW for replenishing hit dice is you get half back per long rest.  This really helps with the economy of the game, because it doesn't have players unlimited HP farming, and it makes clerics and healers very useful.  

Exactly how and when to disrupt a long or short rest is usually up to the DM, but what I tend to do behind the screen is take the highest perception of the most intelligent monster within an area (I estimate approximately 100 feet as the crow flies on the map), and make a check.  Adjust the DC as you see fit based on how many walls and doors are between the party and whatever is looking for it.  Also, think about the monster and how likely it would become a wandering monster.  During a long rest, I do the same thing, but do it every two hours depending on if the party is taking turns on a watch, and decrease the DC each watch (again, according to what you are working with).  If the players aren't setting watches in an area with active threats, I set the DC at a 5 or 10, depending on what I'm working with, or just roll % to see if an attack would happen.  I tend to make it more likely than not that the party will be attacked if there is no watch set, because c'mon.

Also take into account the donning and doffing of armor.  Sure, we have the 24 AC paladin, but if they are sleeping in their armor, they will take a level of exhaustion unless they have some mechanical reason to bypass that by an item, feat, or ability.  If the party gets ambushed, the paladin isn't putting on their full plate anytime soon, always use RAW for donning armor.  Much of this sounds like common sense, but I feel like I run into it a lot in games, and it is one of the details that can seem more tedious and easy to overlook when you are running a game.  

DM-ing games is a balancing act.  If it is too easy, the game gets boring, if it's too hard, players stop showing up.  The rest system in 5e for me, is a great way to let the dice decide the fate of the party, and add just enough randomness to make the players on edge.  Of course, don't always let the dice decide, if the party is due for it, they are due for it.  The same goes for TPK situations when they party is worn out and you could easily wipe them with that CR 5 creature they don't know about.  The real decision comes down to the DM, and I tend to give the party the benefit of the doubt in long campaigns, but that is just me.