Neverwhere (3rd Edition) (2009)

From the publisher:

The third - and probably final - edition of the Neverwhere RPG, produced with permission and available for PDF only. This is the final, comprehensive edition of the game with an improved system, more detail an expanded A-Z and advice for running the game in tabletop, online or as a LARP.

From the book:
From the introduction:

The Neverwhere game is based on the world described by Neil Gaiman in the novel and B.B.C. series of the same name. The game expands on the tantalising details that were revealed to us there, expanding on London Below and filling in many of the gaps with the authors’ imaginations...

You don’t have to have any special equipment at all in order to play the Neverwhere role-playing game. All you really need is at least two people and descriptions of your characters. The standard system uses a ten-sided dice to resolve conflicts and this can be found in any hobby shop or can be improvised using two six-sided dice and taking away two (ignoring a result of zero). Otherwise you can play using resolutions that require no dice at all and this shouldn’t adversely affect the game.