well, i can tell you its just a tag name for any magick that uses blood as a basis of its rituals. Becuase blood is commonly viewed as a life force, using blood in rituals would most commonly be used in things that involve life energy, a very powerful energy force.
Using your own blood would be harnnesing your life energy and merging or connecting it with another, such as in spiritual pacts.
hope this helped
Blood Magick is using blood as a tool in magickal rituals, casting of spells,etc.Blood is very powerful and it should not be taken lightly or used irresponsibly because it can be very dangerous.
I suggest if your going to be withdrawing blood you should clean the area and use sterile objects as to not get infections. Blood diseases do exist so I suggest you don;t go mixing blood, just to be on the safe side. Blood from a woman's menstrual cycle is the most powerful of all.
I personally do not do blood magick because I don't believe a ritual etc should need you to harm yourself in anyway.
People also use blood for making there runes and sometimes cards. This helps to make them more attuned to your energy. Like they said previously, do it in a sterile manner. Also, do not cut yourself, use a needle and do it on the tip of your finger if you can. It is not a good idea to do it anywhere else because you would not be able to monitor it as well for signs of infection. That and you could injure an artery :)
one thing i'd like to point out to everyone, blood magic is not good or evil [same as black/white magic] so don't be scared off by the name, i know of a few protection spells and healing spells that require blood. in fact i know of only one spell with blood that's considered a curse.
Oh like wow i'm back at just the right time. In my travels i come across a guy who's been hunted by his girlfriend's ghost after she passed away. From what i learned he said the girl wants him to go with her, do to the reason that they had drink each others blood and made an oath to be together in life and death. Is there any way he can avoid her now. He is being help by a shamin right now, but still the girl keep on coming back.
I spose, seance would be one suggestion, explaining to her, that its obviously not his time yet, if they were to be together now, he wouldve died with her, but he needs to fullfill something in his life or learn something he hasnt yet learned.
or an exorsicm, but thats kindve hard, depending on how powerful she is.
Now, oaths get broken all the time, just becuase they drank each others blood doesnt mean that theyr bound, its a symbolic representation that they will qalways love each other, but if you want a suggestion becuase he believes in the oath so strongly giving it that energy, tell him to read the oath backwards, or repeat the words that sshe, and he made together, this shuld reverse the energy and take that power that she is feeding off away, making it easier for him to do an exorsicm or a seance.
AND about every two weeks or so this exact question gets posed in the forums, and there are good answers each time. My suggestion, if you wish to learn more, is to do a search of the term and see what past threads come up. For instance, in my old coven, Practical Witches, we had a lengthy forum thread on the topic.