Board Thread:Arrow discussions/@comment-26923997-20160823073858/@comment-25322628-20160829002155

Kaestal wrote: I think there was a storyline about Ra's using all of them up right?

And then... he died. They explained that back before Ra's recruited his daughter, Nyssa, the Lazarus Pits could be used only once. When Nyssa was disowned, Ra's gave her one of the Pits, which she found a way to use repeatedly, allowing her to survive beyond the Second World War. It was never explained how Nyssa discovered the way to reuse the Pit.