Ох блин. Изучай.
http://www.wowwiki.com/Lightwell_(old)?oldid=2328636
Creates a Holy Lightwell. Friendly players can click the Lightwell to restore X health over 6 sec. Attacks done to you equal to 30% of your total health will cancel the effect. Lightwell lasts for 3 min or 10 charges.
However, the primarily complaint was that the healing you receive from using the Lightwell would break on damage, similar to using a bandage. Since Lightwell would be most powerful in AoE heavy fights, in order to heal the dps classes while allowing the healer to focus on the tank, this was risky time to use it since if the dps classes received more damage while using the lightwell then it wouldn't heal them very much.
In patch 3.0, the lightwell talent received further changes: The healing effect now only breaks if damage received equals more than 30% of total health. Furthermore the total number of charges was increased to 10.
Переводчик подкинуть или так справишься? Этот момент долго будоражил игроков, и близзард из патча к патчу переписывали чуть ли не под корень умение, чтобы оно стало усваиваемым игроками и юзалось ними.