Which modern expression comes from the story of Pandora opening her container?

The modern expression “opening Pandora’s box” comes from the story of Pandora opening the container that released evils into the world. Today it describes an action that creates many unexpected problems or consequences.

The phrase is based on a later version of the myth’s title, because Hesiod originally described a pithos, or large storage jar. The “box” wording became influential through Latin and European retellings, then entered ordinary English as a metaphor.

The expression is not limited to mythology or literature. Writers use it for scientific discoveries, political decisions, legal cases, technological changes, or personal choices whose effects become difficult to control. Its meaning depends on the idea that one seemingly simple act can unleash a chain of troubles.

Other common expressions from Greek mythology have different meanings. An “Achilles’ heel” is a vulnerable point, while “crossing the Rubicon” comes from Roman history. Those phrases should not be substituted for the Pandora idiom.