Jet addiction is a form of addiction which can occur in Fallout 2, Fallout 3 and Fallout: New Vegas.
You used the drug Jet once too often and now your body is craving for more... and more... and more... well done! You got yourself addicted.
Everything is moving so slowly... you need to get some more Jet, right NOW!
”— Fallout 2 In-game description
Using Jet carries a 50% chance to become addicted. When addicted to Jet, you suffer from a -1 penalty to Strength and Perception.
Fallout 3, Fallout: New VegasEdit
Using Jet carries a 20% chance to become addicted. When addicted to Jet, you suffer from a -1 penalty to Agility and Charisma.