Fallout: New Vegas lead designer J.E. Sawyer has reworked the balance of Obsidian's post-apocalyptic RPG, amping up the difficulty and tinkering to his own preference. Intriguingly, these changes come in a mod of Sawyer's making, not any official patch.
You can download the tiny 88KB mod direct from Sawyer. To use it, you'll need to have every piece of New Vegas downloadable content installed, including the former pre-order bonus packs. You'll also need Fallout Mod Manager or the like.
As for why this is a mod rather than a patch, Sawyer explained that as well as technical reasons, "some of the mechanics changes make the game significantly more difficult... or at least more of a hassle... I'd rather have people opt-in to those changes than make them the default in a patch."
He added, "the game's over. The ship has sailed. No one is working on it anymore. No testers, nothing. This mod is just me working in my free time. If I horribly botch something, you can just un-check the mod and go on your way."
An Ultimate Edition of New Vegas, complete with all of its DLC, is due on February 7.