"When anything is destroyed with balefire, it ceases to exist before the moment of its destruction, like a thread that burns away from where the flame touched it. The greater the power of the balefire, the further back in time it ceases to exist. The strongest [Moiraine] can manage will remove only a few seconds from the Pattern...For as far back as you destroy [something], whatever it did during that time no longer happened. Only the memories remain, for those who saw or experienced it." [TFOH: 6, Gateways, 119]

That pretty much explains it. Something that is BFed is erased backwards in time; the amount of erasing depends on the amount of Power put into the BF. Rand, at full power, with an angreal, managed to erase Rahvin back about half an hour. Note that balefire does NOT erase every single action the victim performed in his life. When Rahvin was BFed, Morgase did not become un-Compelled, sitting back in the Caemlyn palace. If Lanfear were balefired, the Bore would not cease to exist, since it was created over 3000 years ago, and I doubt that the capacity for creating that strong a beam of BF exists. (Plus, if it WAS done, the poor Pattern would probably unravel completely; see below.)

If person A balefires person B, and then person C balefires person A, does person B come back to life?

This one has cropped up time and again over the years, but RJ appears to have contradicted himself over the answer.

For instance, William Carew reported that RJ said, at a Brisbane signing in 1999, that if the balefire from Person C was strong enough, then yes, Person B would come back to life.

But, contrariwise, Paul Ward received a letter from RJ (dated March 2000) in which he stated, "The balefire weave exists wholly or partly outside time, which removes it from its own effect." Which implies the opposite.

When a person is balefired, can he be reborn?

The description of balefire leaves us one important question: does "burning one's thread from the Pattern" mean that one's soul is destroyed forever, and one can never be reborn? John Novak finally got an answer for this from RJ at a post-TPOD book-signing [Northern Virginia - 21 November, 1998]:

Balefire: I'm right. (This was my question) What this means is, if someone is balefired, the Dark One can't reincarnate them. But they CAN be spun back out into the wheel as normal. Balefire is NOT the eternal death of the soul. He also made a comment to the effect that even in the absence of balefire, there may be circumstances where the Dark One cannot bring someone back.

If this is the case, then why is BF so bad? It must be a question of scale. If lots of BF is used on many targets, as it was during the War of Power, the Pattern will become quite ragged and begin to unravel, like an old pair of jeans. If large quantities of BF are used, then there will be obvious problems with causality, as there were in the aftermath of Rahvin's death. Thus, it's not a good idea to use strong BF, and it's not wise for many people to use it regularly.

John Walter Biles explains: The Pattern unravels permanently because in a war of mass destruction with balefire, you can yank threads out of the Pattern faster than they can be replaced. Yeah, they can EVENTUALLY be reborn, but unless the total population of all of creation is static, then they won't be reborn instantly. More importantly, it screws up causality. That's why the Pattern can unravel; it's not that you run out of threads, it is that if you nuke an entire city, every consequence of every action by everyone in the entire city is suddenly undone back to point X. Given the amount of balefire nuking a city takes, you can make quite a mess. Do enough damage to the Pattern faster than it can repair itself, and it still comes apart.

So if a balefired person can be reborn, why can't the DO recycle a Forsaken that's been killed by balefire?

The real question being asked here is: what is the difference between the soul of a Forsaken killed by ordinary means and the soul of one killed by balefire? Timothy Itnyre explains:

"The only difference is that the Forsaken killed by balefire dies in the past; at the moment of contact with the balefire, they are already dead and their soul has gone on to wherever souls go when you're dead. In a normal death, the Forsaken's soul departs at the moment of death. The only difference then is the timing of the soul's departure. This would indicate that the Dark One's inability to resurrect balefired souls has to do with the timing rather than actual physical properties of balefire. In LOC, the Dark One laments his inability to resurrect Rahvin: '"RAHVIN DEAD IN HIS PRIDE. HE SERVED WELL, YET EVEN I CANNOT SAVE HIM FROM BALEFIRE. EVEN I CANNOT STEP OUTSIDE OF TIME"' [LOC: Prologue, The First Message, 15].

"The crucial clue is in the last line where the Dark One says that he cannot step outside of time. The Dark One must claim the Forsaken's soul before it goes off to the afterlife; in the case of a balefire victim, the Dark One would have to go into the past to get the soul. Since the Dark One cannot step outside of time, he cannot save those souls. Therefore, balefire prevents the Dark One from claiming souls."

Why doesn't somebody just balefire the Dark One back to before where the taint was created?

Read the previous paragraphs about what BF does, and why it is dangerous to use. Now, supposing that 1) the DO has a corporeal body which could BE balefired, and 2) enough BF could be produced to zap the DO back 3500 years (neither of which is at all certain), consider what would happen to the poor Pattern of All Creation if one of the prime movers in its weaving was BFed. The end of the world would probably happen for sure, then.

Remember that the DO is the source of the whole history of the Third Age. Everything everybody has done for the past 3500 or so years has been affected in some way by the DO. Why is Joe Al'Schmoe of the Two Rivers a farmer in a forgotten province of Andor, and not a citizen of one of the most powerful, strongest nations in Randland? It's because Manetheren was destroyed in the Trolloc Wars, which were initiated by Ishamael, who was the DO's right-hand-man throughout the Third Age.

Another point (via G.G. Kay's Fionavar Tapestry) is that maybe the DO doesn't even have a thread to balefire. After all, the DO's prison exists "outside the Pattern." Perhaps the DO itself does, too. (NB: the no-body/no-thread argument applies to "Why doesn't somebody BF the DO," no matter if you try to BF him back 3500 years or 3 seconds. The "Pattern" argument does, as well - if there is no DO, what happens the next time the Wheel comes around to the AOL/Third Age again?)