Resting Rule-Set

Notice: These rules are still in development and can/will be tweaked.

Short rest

A short rest is a period of downtime, at least 1 hour long, during which a character does nothing more strenuous than eating, drinking, reading, casting cantrips, and tending to wounds. A character can spend one or more Hit Dice at the end of a short rest, up to the character's maximum number of Hit Dice.

Long rest

A long rest is a period of extended downtime, at least a full day, during which a character sleeps for at least 6 hours. If the rest is interrupted by a period of strenuous activity - at least 10 minutes of running, 1 hour of riding or walking, fighting, casting leveled spells (excluding ritual spells of 3rd level or lower), or similar adventuring activity - the characters must rest for a further 6 hours to gain any benefit from it.
At the end of a long rest, a character can spend one or more Hit Dice, up to the character's maximum number of Hit Dice. The character then also regains spent Hit Dice, up to a number of dice equal to half of the character's total number of them (minimum of one die). For example, if a character has eight Hit Dice, he or she can regain four spent Hit Dice upon finishing a long rest.
A character can't benefit from more than one long rest in a 3 day period, and a character must have at least 1 hit point at the start of the rest to gain its benefits.

Full rest

A full rest is a period of extended downtime, at least 3 full days, in decent conditions and during which a character sleeps for at least 6 hours per day. If the rest is interrupted by a period of strenuous activity - at least 30 hour of running, 3 hours of riding or walking, fighting, casting leveled spells (excluding ritual spells), or similar adventuring activity - the characters must rest for a further full day to gain any benefit from it.
At the end of a full rest, a character regains all lost hit points and also regains all spent Hit Dice.
A character can't benefit from more than one full rest in a 9 day (week) period, and a character must have at least 1 hit point at the start of the rest to gain its benefits.

Decent conditions

While bedrolls laid out around a campfire may suffice for a short rest or long rest while travelling, it does not provide decent conditions. To be in decent conditions the player must have the following: full protection from the elements; a good, sustainable source of food, water, and heat; adequate bedding.
The exact criteria for whether a location provides decent conditions is decided by the DM. Examples of locations that do provide decent conditions may be an inn, townhouse, castle, or a permanent camp.
If players take a short or long rest in decent conditions, double the result of any Hit Die rolled to regain hit points.*

Full Day

A full day may be started at any time and does not have to be exactly 24 hours. The length of time that qualifies as a full day is decided by the DM depending on when it was started, weather conditions, location, player activity, etc.

Class, Race, Item Features

Whenever a feature or item property mentions rests (e.g. you regain this ability when you take a short rest), use the new rest length with the same name.
Essentially no features, item properties, etc are dependant on the new full rest that has been added.

*This effect does not stack with any similar effects gained from spells or magical items.