RETAIL USERS
Right click the icon you use to start the game, go to properties. Add "-console" to the end of the executable. It should look like:
"C:\Program Files\Activision\Vampire - Bloodlines\vampire.exe" -console
STEAM USERS
Right click VTMB game within Steam, select "Properties" -> "Set Launch Options". Enter "-console" within the input box to enable console.
USAGE
Only use the TILDA key (~/`) to open and close console.
Only use the console from the Load/Save game menu screen (or your game may lock up).
Be certain you load or start a game before issueing any commands.