Wands changing hands
Ive read the books and seen the movies, but theres one thing Ive never understood: exactly how does a wand change hands?
We know that you have to defeat the previous owner to make it yours. But we saw that Draco became the master of the Elder Wand simply by disarming Dumbledore, so we know that you can take someones wand with the Expelliarmus spell.
And heres what I dont get: if thats all it takes to win someones wand, then theyd have to change owners pretty often, wouldnt they?
For example, when Snape disarmed Lockhart with the same spell in CoS, did he become the master of Lockharts wand?
Or can this only happen if you disarm someone in a duel? And in that case, does the loser continue to use the wand, even though its technically no longer theirs?
And what are the actual advantages of using your own wand, and what are the disadvantages of using one thats been taken from you?- apart from the strength of the spells you cast, obviously.
I think the only advantage that was mentioned is that a wand refuses to kill its master, which is why Voldemort couldnt kill Harry with the Elder Wand, but other than that, I dont think this was discussed.
Either I missed something, or this wasnt explained properly.
Can someone explain?