- Must play in hardcoe (duh)
- Sleep is required every 48 hours (minimum)
- Sleep is only permitted in unowned buildings, or rooms you have rented/bought
- You can *only* save the game before sleeping, never during your trip
- Rex and ED-E cannot be used to store items
- Difficulty must be Normal or Hard
- You cannot eat/drink/inject when in [Danger]
- HUD must be set to 0% opacity unless using Power Helmets/Ranger Vet. Helmet
- You can't use your Pipboy while in [Danger]
- Using the "Wait" feature is not permitted
- You are permitted to 3 weapons, and only 2 of them can be two-handed
If you need a real challenge, give this a go. It basically makes the Fallout experience as difficult as possible.