First off, sory this is in the wrong section, i do not have enough rep to place in orrect section.
Anyway, basically, go into the Dalalran sewers and duel somebody. Im not 100% sure but if you are about to finish the duel the person about to lose will stay at 1hp, and take any amount of dmg and not die or lose the duel. Pretty fun to toy around with. Will check if falling dmg/etc outa duel dmg wil not occur.
EDIT:: Taking this damage will cause you doing to full hp, and taking the dmg from full hp. So if i fall 1k dmg at 1hp, and my total hp is 5k, i will end up with 4k hp.
Enjoy!