In Harry Potter and the Half Blood Prince:
The original plan is for Snape to kill Dumbledore, but before he can, Draco Malfoy disarms Dumbledore, which (even though he doesn't know it), transfers control of the Elder Wand to Draco before Snape can kill Dumbledore.
This becomes an issue later, in Harry Potter and the Deathly Hallows:
Voldemort knows he doesn't have control of the Elder Wand and thinks it is Snape's, so he kills Snape to win the Wand's obedience, but this doesn't work because Snape was never the Wand's master.
We know that what took place in Half Blood Prince was planned out by Dumbledore because:
Dumbledore would die within a year, in a painful way, due to the trap he was caught in when he was searching for Voldemort's horcruxes.
Which leads me to wonder:
If Dumbledore had not been disarmed or killed in Half Blood Prince, and he died as a result of the trap set for him, would Voldemort have won the Elder Wand? There was no duel, no direct contest, and no use of wands to combat each other, just a sneak trap left behind to protect the horcrux.
So would a trap or something similar that kills a person still be enough to win the Elder Wand, or does it have to be won through the use of wands or some type of actual combat?