Ol' Slim, otherwise known as Slim, is an old-time adventurer from the Fallout world.
Slim's name comes from how resources and rewarding opportunities are considered to be slim in New California. Slim is familiar with Vault 13, hearing rumors about the Vault, as well as considering if anyone was alive within it. His various wasteland adventures have led to encountering creatures like Radscorpions, cave rats, and even Deathclaws. His humorous, honest and frank advice based on his vast experiences can be found in the Fallout Official Survival Guide as additional notes.
- Slim has been referred to as "Desert Rat," "Prospector," and "Pops", although not directly.
- Slim directly carries a copy of the Fallout Official Survival Guide, giving it to the Vault Dweller in the prologue.
Ol' Slim is only referenced as an author of various advice in Fallout Official Survival Guide.