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.

The mod, spotted by No Mutants Allowed, cuts the level cap, XP gain, health and healing, while also sprucing up a number of weapons and armour. A few more highlights are this-a-way.

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.