Question: is a series of unfortunate events based on a real story

Answer: No, The author of the series, Daniel Handler (who uses the pseudonym Lemony Snicket), has said in an interview with The A.V. Club that he decided to write a children's story when he was trying to find a publisher for his first novel, The Basic Eight. One of the publishers, HarperCollins, passed on The Basic Eight, but they were interested in him writing a story for children. Handler thought it was a terrible idea at first, but met with the publishers to discuss the book. They challenged him to write the book he wished he could have read when he was 10. He retooled a manuscript he had for a mock-Gothic book for adults, which became ``the story of children growing through all these terrible things'', a concept which the publishers liked, to Handler's surprise.