Well, I played FO3 a few years ago, but never really played it as an RPG. This time I want to, but I need a bit help.

1. Please fill me in on the lore. Not the most basic things, but still basic things. (most basic: The 3 superpowers nuked everything) (basic: What is the enclave)

2.The Crashes to Desktop. Every... 30...minutes... I'm on PC, modded. I downloaded the most popular crash fixes and performance boosters. Even a clean game crashes every 30 mins. How do I solve this?

3. In what rate should I level my Lockpick/Science skill against my offensive skill, and speech?

4. In my previous playthroughs I easily ran out of Stimpacks and food at higher levels. Any advice?

Please focus on lore once the last 3 questions are answered Thanks in advance.