An acronym for "Vampire: The
Masquerade", a
tabletop RPG written and published by the staff of the RPG company White Wolf. One of their most popular and (in)famous games, it was discontinued recently (as of this writing). The "heir to the throne" is "Vampire: The Requiem", a similarly structured game with a different backstory and rule system.
Vampire is one of several tabletop RPGs that comprise White Wolf's "World of Darkness" games, and has a not wholly undeserved reputation of attracting goths and the
disenfranchised.