Whenever a spell or ability an opponent controls destroys a noncreature permanent you control, you may destroy target permanent that opponent controls.
A spell or ability that asks for a sacrifice will not trigger this card.
If an opponent destroys Karmic Justice, it will trigger on its own destruction.
Karmic Justice will not trigger if an opponent’s spell or ability causes your permanent to be destroyed indirectly. For example, if the spell caused an ability you control to trigger, and thereby destroy your permanent.
Karmic Justice will not trigger off of its ability destroying a permanent since you destroy the permanent and you are not one of your opponents.