Logan's Loophole

"No one's going to put you out to pasture 'cause you're going to stay young (and level 30) forever! You'll never again become addicted to chems, and they'll last twice as long... but after 30 you can kiss experience, perks, and skill points goodbye!"

- Fallout: New Vegas description

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

Effect
Chems last twice as long and you never become addicted but your character 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.