The Five-Minute Adventuring Day
D&D Fifth Edition defines a long rest as "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." At the end of the long rest, characters regain all their lost hit points and reset all their class and subclass features. They set out afterwards completely refreshed, as if it were the first day of their adventure.
This system makes it very easy to manage resources, as you simply reset everything in the morning. However, it has led to a problem called the "five-minute adventuring day," where characters take a long rest after engaging in just one or two encounters in order to replenish their resources. They can then enter each encounter and blaze away with their most powerful features. This practice virtually eliminates the resource management aspect of the game, which is a great loss. Players miss out on those dramatic moments in a game where the wizard is counting spells or the fighter is weighing up when to use their action surge.
Historically, dungeons were designed as resource-draining environments. Hence, the over-frequent resting allowed by the current system diminishes both the danger and the drama of this core environment. It leads to battles with the same shape, with characters using their best abilities in every fight. This shift may explain why dungeon crawls, once celebrated as the epitome of adventure, have lost some of their appeal to many modern gamers.
Wilderness travel suffers from a similar problem. Since travel systems typically mandate only one or two daily encounters, players can expend all their resources knowing they will fully recover overnight. With the rules as they are, it is impossible to conjure the experience of attrition and mounting danger that a long journey through the perilous wilds should entail.
Designers have proposed various solutions to this problem. The Dungeon Master's Guide contains a rest variant called "gritty realism," which mandates a short rest duration of 8 hours and a long rest of 7 days. I find this too onerous for a fantasy campaign. But I've devised a system that fits somewhere between standard 5E and gritty realism that has worked well at my table.
Short rests remain as is. Long rests also retain the normal duration (8 hours), but with this additional caveat - you must be in a settlement (i.e., village, town, city) to profit from them. Sleeping in an improvised campsite, whether beside the road, in the forest, or somewhere in the dungeon, is not considered a long rest. There are some corner cases regarding what constitutes a settlement (such as an isolated farmhouse on a lonely moor), but they can be handled by DM fiat.
I've been using this simple rule for a while now, and it really restores a thrilling dimension to the game. Exploring a dungeon requires careful resource management because you can't simply "hole up" in a room, block the door, and emerge fully charged again in a few hours. And a ten-day journey through the wilderness becomes a serious undertaking, with each encounter depleting resources you cannot quickly replenish. Stumbling upon a Rivendell-like settlement during such a journey is like a kiss from the gods.
What about a situation where the characters plan to explore a large wilderness area? This style of play may not be feasible if the characters are firmly tethered to a settlement. One solution is to let the party create a "secure camp." Such a structure is not just a few tents pitched on the side of the road--instead, it is a well-hidden and protected site that serves as a base of operations for further exploration. Setting it up requires significant effort. Finding the appropriate location needs a day of searching and a successful DC 10 Wisdom (Survival) check. Setting up the site requires another day of work and another successful DC 10 Wisdom (Survival) check. Once the characters have set up a secure camp, they can take long rests there.
Beyond just mechanics, limiting the availability of long rests immerses the players more deeply into the game world. When settlements become more than just a place to buy gear but a sanctuary for survival, the characters' connection to the world grows. Wilderness exploration and dungeon crawling become more daunting but also more rewarding. In this way, the campaign world feels more vital and dangerous, reinforcing the atmosphere of adventure that defines fantasy role-playing.