News.com.au says: IT'S not every day you play a video game that requires tens of thousands of pages to explain what it's about.
But as fans know, Fallout: New Vegas isn't just any old game.
The latest instalment in the dystopian sci-fi series is an epic tale of war and diplomacy set in the Mojave desert, decades after a nuclear apocalypse.
The plot is part pulp crime novel and part The Good, The Bad and The Ugly, with hundreds of different variations depending on your decisions.
To play through just one of the several possible storylines can take up to 50 hours, so it's little wonder that players often go looking for a little help when they come to the crossroads.
That's where The Vault comes in. It's an enormous repository of knowledge about the Fallout universe maintained by a community of fans in a similar way to Wikipedia.