| ||For the condition in Fallout 3 and Fallout: New Vegas, see Well Rested.|
Rented rooms always work and beds built by the Sole Survivor in settlements work, if no settler has been assigned. Assigning a settler to a bed will prevent the Sole Survivor from using it, as it is now owned.
In Survival mode, the player character must sleep for at least 7 hours to obtain the perk, meaning sleeping bags and mattresses cannot be used, as they only permit 3 and 5 hours of sleep respectively. However, in this mode, any bed may be used to obtain this perk, so long as the bed is not considered owned by someone else and the player character is not currently trespassing or incurring radiation damage.
- +10% XP for a limited time (8 in-game hours).
- In Survival mode, the effect also grants +2 to Endurance and Agility.
- If sleeping while in the company of a companion with whom the Sole Survivor is in a romantic relationship, instead of the Well Rested perk one will receive the Lover's Embrace temporary perk, which increases XP earned by 15%.
- Fast-traveling jumps the in-game time forward by an amount that depends on the distance traveled, up to a little over 14 hours from the farthest corners, which would negate the well rested bonus.
- The Sole Survivor can mitigate the traveling time by using the Institute as a jumping platform as it only takes 1-game-minute to teleport to and from the Institute.
- PC Reducing the game timescale using console commands reduces fast travel time as well as game time.
- It is possible to sleep for zero hours by canceling the sleep as soon as the background goes black without time passing. The bonus lasts for twelve hours from the time of waking up, regardless of the time spent sleeping.
- Sleeping before the perk has run out causes the perk to be refreshed for another 8 in-game hours.
PC Sometimes both the Lover's Embrace and the Well Rested bonus are given, adding up to a total of +25% experience while they last. Once the 8 hours are over, both perks expire with no known side effects.[verified]