Half-Life 2: Raising the Bar (or HL2: RTB for short) is a coffee-table hard-bound book offerred by Valve that details the development of the Half-Life series, including mods and the original Half-Life, although the focus is on Half-Life 2. It includes many pieces of artwork and information that are not available elsewhere, and also includes various plotlines, characters, aliens, and locations that were not included in the final versions of the games.
Valve currently offers Half-Life 2: Raising the Bar for $24.95 on their website's store, although it is not known for how much longer as the book was originally intended to be a limited edition.
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Raising The Bar
