Logan's Loophole

Logan's Loophole is a trait in the Fallout: New Vegas add-on Old World Blues.

Effects
Chems last twice as long and removes the possibility to become addicted, but the player character's level will be capped at 30.

Behind the scenes
This trait is a reference to the 1976 science fiction film Logan's Run, based on the 1967 novel of the same name. Citizens in the film are executed after becoming 30 years of age, hence the level cap 30 of this perk. However, in the original novel, this age limit was 21, not 30.