There are 3 kinds of rests your adventurers can take part in: Night’s Rest, Safe Rest, and Downtime.
A Night’s Rest is simply spending the night in the wilds. It is often uncomfortable, draining, resource intensive, and you can’t sleep well because your guard is up. There are things you can do to improve your rest (see Comfort below). A Night’s Rest isn’t restful enough to allow spell casters to prepare spells of the 2nd Circle or higher.
A Safe Rest is spending the night in a safe location. Most of the time, this is a location like an inn, or another person’s house, or even your own property.
Downtime is spending significant time doing non-adventuring things. The players handbook grants some ideas on how to handle downtime events, but largely this is collaborative between a GM and the players. Spells of the 3rd Circle take significant time to recover, and thus spell casters must spend at least part of their downtime preparing them if they wish to cast them again.
Resting is one of the most important aspects of In the Dark and the Deep. Although certainly special, your character is still mortal, and braving the dark and deep places of the world has a marked effect on your body. Proper rest and recovery is critical to survival.
Resting is the primary non-magical way of recovering both Grit and hit points.
A Night’s Rest involves getting 10 hours of rest while in a dangerous environment. This includes at least 4 hours of sleep, 2 hours of taking a watch, 2 hours of camp activities (including eating, drinking, interacting with your allies, setting up and taking down camp), and 2 hours of adventuring preparations.
When determining a Night’s Rest, comfort levels are important, and most night’s rest will use the comfort system detailed below. The higher your comfort, the better the rest you can get, and the better the rest you can get, the more Grit you recover. Additionally, it could speed up the rate at which you recover from actual wounds (hit points) if you end up needing to spend extended time in the wilderness.
A Safe Rest involves getting 12 hours of rest while in a safe environment, most commonly an inn or similar building. This includes 8 hours of sleep, and 4 hours of miscellaneous tasks before and after bed. Safe Rests assume food and drink with the rest, and your characters need not “sleep with their eyes open”, so they can relax and let their guard down more. Safe Rests are common during long journeys, or when going back to town for a night to two.
Each night of a safe rest restores 50% of your grit.
Each night of a safe rest removes 1 level of exhaustion.
It takes 7 days of safe rest to recover 1 hit point. During this time, you cannot take grit or hit point damage, or it resets the the timer.
In order to take advantage of one of these items, you must do it the entire time you are resting. For example, 1 day of bed rest doesn’t actually reduce the time between hit point recovery. You must instead spend all 6 time in bed rest.