When I first started playing this game, I realized several things.  First, the single player is pretty weak.  This game was obviously designed as primarily a multi-player game.  Single player CAN be fun, but for a RPG, the game is pretty linear.  I mean, you can pick from several pre-designed phrases when talking to certain NPC's.  According to what responses you pick, your "humanity" rating will either be raised or lowered.  Humanity is basically defined as how "human" your character still is.  In other words, if your character has low humanity, then you are closer to becoming a monster, and if it drops completly to 0, then you don't have any more control over your character, and you have to start from you last save point.  Naturally, only the most sadistic and demented players will actually reach a score of 0, as you literally have to go and kill civilians over and over to get a score that low.  However, I've found a way around this.  If you use the spell "Theft of Vitae", you can get all the blood from humans you want, and your humanity score will not be lowered!  Yet, if you "feed" from a human (meaning you bite the person and drain their blood in the "traditional" vampiric way) and actually kill them through doing this, your humanity score will go down.  The manual is also not very clear on what raising your humanity actually involves.  I literally had to play through the game several times before I realized what things I had to say in order to have a higher humanity rating.  However, at the end of the game, if your humanity is very low, let's say 5 (out of 100), the last boss will say something to you, and you will have three choices to pick.  Thus, you can get all three endings by having a low humanity score!  Yet if your humanity score is high, (I think above 50), then you only get the "good" ending, and you can't even see the other ones!  Obviously, then, there's almost no incentive to keep your humanity high, which is one of the most critical (and tragic) elements of any Vampire:The Masquerade game.