I have the 20th anniversary edition of the Masquerade.
The book clearly states at some point that when a vampire drinks blood, and even it's from a willing human that the vampire does not want to kill, there is a risk that the vampire drinks too much blood and kills the human.
I could not find a precise rule in the book regarding that risk. Is there a self-control test or something like that?
Thanks in advance.
There are two systems to look at for this.
Each point of blood that's consumed deals one level of lethal damage to the victim. A strong, healthy vessel can take two or three levels of damage and be expected to recover just fine in time if they get proper rest.
But not every mortal victim has all seven of their health levels to begin with. Someone who is very small (children, dwarfs, petite adults) will have less blood to lose. Someone who is sick or injured will already have damage to their health track, meaning that drinking a point or two of their blood could push them over the edge. This is among the reasons why real-life blood banks have a questionnaire they ask before accepting a donor, and will reject some people.
Since vampires are rarely doctors and many medical problems don't have obvious external signs, an unlucky vampire can send a person to the hospital or kill them without intending to.
Page 285 to 286 of V20 covers mortal damage and healing rules.
Look at the chart for Frenzy on page 298. The smell, sight and taste of blood are all provocations that will call for a roll if the vampire is hungry. If a vampire hunts normally while they are especially hungry, they will be tasting blood once they bite into the victim. That can cause a Frenzy check. Once in hunger Frenzy, the vampire is going to drink quickly and greedily.
Ending a Frenzy is at the Storyteller's discretion, though one scene is typical. STs sometimes rule that a frenzy ends on its own if the provoking stimulus is removed. For example, you might be able to make a new Self-Control check to end a hunger frenzy once you have drunk enough to no longer be hungry. It is never guaranteed to work, and the ST may not allow it.
Even a round or two of hunger frenzy while feeding can be enough to kill a person, so ending a frenzy early won't always save the victim. A vampire can drink up to three points of blood per round (with a "normal" mouth. Certain deformities or shape-shifting can change this).
When a vampire's blood pool drop below (7 - Self-Control/Instinct) blood points, rounding up, they will be hungry enough to be making Frenzy checks. Getting near that amount the vampire feels uncomfortable and hungry, but not so strongly that frenzy is an immediate concern.
Because the Frenzy rules are explicitly left vague for ST interpretation, you should also talk to your ST about how they define "hungry" and when they'll generally be asking for rolls. If you're the ST, ask yourself these questions and consider how you want frenzy to impact your PCs and their story.
Extreme situations can and should bend the normal rules. The "sight of blood" will normally provoke frenzy only when hungry. However, if a vampire suddenly and unexpectedly finds herself standing in a room that's completely covered in fresh, glistening blood, that might be a strong enough provocation even if she isn't very hungry.
Since the question has the "old-world-of-darkness" tag, I'll also throw in my two cents.
In the Vampire the Masquerade rulebook it states: "A vampire may take only 20 percent of a vessel's blood and leave it relatively safe. Taking half of a vessel's blood necessitates hospitalization for that vessel." (p. 139) On the same page it also states that average human has 10 blood points, leading to five being half of that.
Wikipedia article on hypovolemia (http://en.wikipedia.org/wiki/Hypovolemia) states that losing over 40% of ones blood leads to stage four hypovolemic shock in which "survival is extremely unlikely". I also seem to recollect a first aid trainer saying losing half of ones blood leads to immediate cardiac arrest.
In our VtM games, the following "chart" is applied to human victims drained of blood. I've also added the comparable level of damage on the seven-tiered damage-chart.
Points taken. Effects
- Slight weakness. Heavy physical activity (combat, exercise...) may incur -1 penalty. Victim is fine in a day. Victim is Bruised (1 point of lethal).
- Weakness and slight disorientation. Victim needs to eat well and drink a lot of fluids. Victim is Injured (3 points of lethal).
- Semi-conscious and weak. Will recover in good conditions on her own. Victim is Mauled (5 points of lethal).
- Unconscious and poorly. Likely needs someone to take care for her for a day or two. Hospitalization a good idea. Victim is Crippled (6 points of lethal).
- Unconscious and hanging on for dear life. Will die if not taken to a hospital within the hour. Might suffer permanant damage. Victim is Incapacitated (7 points of lethal).
- Quite dead. If receives immediate critical medical assistance, might make it (I'd make it a 1/10 shot). Victim is Incapacitated (7 points of lethal), but likely has suffered permanent damage.
- or more. Dead.
Typical rule of thumb in our games is that three points is the critical limit after which the victim needs assistance to make it. Maybe not from a doctor, but still some assistance.
One should also note the environment where the blood is taken from the victim. It is one thing to drink three points of blood from a victim in the comfort of their own home and entirely different to drink these points behind a dumpster in an alley in freezing weather. In the first case the victim will likely wake up next day, feel awful for a day or two and continue about their business. In the latter case there is a good the victim dies of hypothermia before she gains her strength.
