What idiom describes an action that creates many unexpected problems, inspired by Pandora’s story?

“Opening Pandora’s box” describes an action that creates many unexpected problems.

The idiom comes from the Greek myth in which Pandora opens a container holding destructive forces. Once released, these troubles spread through the human world. The expression is now used figuratively when an apparently simple decision produces a chain of difficult, often irreversible consequences.

The phrase is related to, but not identical with, “opening a can of worms.” Both expressions describe creating complications, but “opening Pandora’s box” specifically invokes the ancient myth and often suggests that the consequences were unforeseen. It can be used in journalism, politics, law, science, and everyday conversation.

The idiom’s wording also preserves the later translation tradition that changed Hesiod’s jar into a box. In the original Greek account, the container was a pithos. Nevertheless, “opening Pandora’s box” is the established English phrase and the usual figurative reference.