Psycho Addiction

 is a form of addiction which can occur in Fallout, Fallout 2, Fallout 3, Fallout New Vegas and Fallout Tactics.

Fallout, Fallout 2, Fallout Tactics
Using Psycho carries a 20% chance to become addicted. The addiction lasts for 1 week.

Fallout 3, Fallout New Vegas
Using Psycho carries a 20% chance to become addicted.

Behind the scenes

 * The picture is a reference to several horror movies. The hockey mask refers to Friday the 13th, the long claws refer to A Nightmare on Elm Street, and the chainsaw is a nod to The Texas Chainsaw Massacre as it says "Made in Texas".