Sleeping in any bed, sleeping roll or pile of hay typically grants a temporary passive ability with varying levels and effects. Any length of sleeping will suffice, even a one hour nap.
Beds in houses owned by the Dragonborn provide better bonuses than other beds. Sleeping in a bed in a room that has been rented at an inn also provides better bonuses than other beds.
Effects can be seen on the Active Effects section of the Magic Menu.
Types of Effects
Rested
When the Dragonborn sleeps in someone else's bed, with the owner's permission, they gain the "Rested" ability. While this status is active, the Dragonborn will gain 5% more experience for eight in-game hours.
This effect can be overridden by The Lover Stone which confers the Lover's Comfort bonus for as long as the stone's effect is active, meaning the Rested effect won't be granted if the stone is active without using an exploit.
Well Rested
When the Dragonborn sleeps in an inn or in a bed that they own, they gain the "Well Rested" ability. While this status is active, the Dragonborn will gain 10% more experience for eight in-game hours.
This effect can be overridden by The Lover Stone which confers the Lover's Comfort bonus for as long as the stone's effect is active, meaning the Well Rested effect won't be granted if the stone is active without using an exploit.
Lover's Comfort
When the Dragonborn is married and sleeps in the same building as their spouse, they gain the "Lover's Comfort" ability. While this status is active, the Dragonborn will gain 15% more experience for eight in-game hours.
If the Dragonborn's spouse is their follower, they will receive this bonus after sleeping in any bed.
This effect can be duplicated by The Lover Stone which confers this bonus for as long as the stone's effect is active, however the effect won't be granted if the stone is active without using an exploit.
Vampiric Blood Rested
In Dawnguard, sleeping in a coffin as a vampire or Vampire Lord will apply the "Vampiric Blood Rested" bonus that grants a 10% Resist Magic effect for eight in-game hours.
Mother's/Father's Love
In Hearthfire, after building a house and adopting a child, the Dragonborn receives the bonus "Father's Love" if male, and "Mother's Love" if female when sleeping in the house that their children occupy. Healing spells and potions add 25% extra health for eight in-game hours.
Waiting
If no bed is available, the Dragonborn can wait. Waiting restores health, magicka, and stamina, but does not provide any other bonuses.
Exploit
To gain the Rested, Well Rested, or Lover's Comfort bonus while using The Lover Stone, unequip the Aetherial Crown (containing the Lover Stone's power) before sleeping and re-equip it after obtaining the Well Rested or Lover's Comfort bonus. Combining this with another Guardian Stone can allow certain skills to level up 50% faster.
Trivia
- Werewolves receive no bonuses from resting, no matter how long they rest.
- The ratio of real to game time is 3 minutes (RT) = 1 hour (GT), so the bonuses last twenty four (RT) minutes. (Also, 1 Skyrim day = 72 RT minutes)
- Unlike previous Elder Scrolls games, sleeping is not necessary to level up.
- It is not possible to sleep in an owned bed or when enemies are nearby.
- Waiting is not possible when enemies are nearby.
- In Dragonborn if the Dovahkiin sleeps, they may awake to find themselves controlled by an all-maker stone.
- Sleeping is the only way to get in contact with the Dark Brotherhood once the prerequisite is met.