Resting

Resting is a gameplay mechanic in Fallout and Fallout 2, Fallout 3, Fallout: New Vegas, Fallout 4, Fallout 76, and Fallout: The Roleplaying Game

Fallout/Fallout 2
The player character can rest to recover their health in almost any place, as long as they're not in combat, using the Pip-Boy 2000 alarm clock function. A handful of places prohibit resting. On the top left of the Pip-Boy screen, a bell icon is next to the date and time. By clicking on the bell, one can choose between several options to rest. Companions may also benefit from this in the way of health regeneration.

Locations
Player characters cannot rest:
 * In the toxic caves
 * In Vault City Downtown

Fallout 3
In Fallout 3, Sleep modifies Hit Points. Sleep is a consequential statistic of the total time spent awake: the longer one is awake, the higher the sleep value becomes. Beverages containing caffeine will reduce this value, as will sleeping in a bed.

Fallout: New Vegas
Sleep is measured in Hardcore mode as "SLP" in the Pip-Boy 3000. Sleeping in an owned or rented bed will give the Well Rested bonus for 12 hours. Each hour of sleep will reduce the SLP meter by 58. As sleep deprivation worsens, stats will be negatively impacted, starting with Agility. Not sleeping for two weeks equals death.

Bugs
Sometimes the SLP meter on the Pip-Boy 3000 can get stuck on zero, and in fact will not display any number below the indication arrow. This is normally caused by traveling through canyon wreckage, which sets all hardcore meters to zero. During this time the PC will not advance into sleep deprivation. This bug may be fixed by finding a bed and sleeping for any amount of time. After the PC awakes, the gauge will display the number and resume its normal function.

Fallout 4
In Fallout 4, Sleep modifies Fatigue in Survival mode. Sleep deprivation is displayed as an icon just below the AP bar. If sleep deprivation is left untreated it will directly impact available Action Points (AP) and SPECIAL stats.

Stages of sleep deprivation
Each of the stages below lasts for exactly 14 in-game hours, or 42 real-time minutes, before progressing to the next.

Fallout: The Roleplaying Game

 * Action Points gained based on time slept.