Shows what happens when you leave Vault 101. The safe and switch right outside Vault 101 are added by the PC mod called choose_XP (ID #2812 at Fallout3Nexus). It lets you change your rate of XP gain on the fly by using the item. Shows lockpicking and one of the Enclave's roaming eyebots.

There are other mods in use here, a few minor texture replacements, but this is pretty close to vanilla gameplay at this point.

I tend to leave Choose_XP set to the default (or 100%) level for the first half a dozen levels. Then once I get up around 8-12 and have a good set of skills, I back off to 50% XP. If I still feel like I'm leveling too fast and not managing to explore enough, I'll back off to 33% XP.