Original: The libretto was adapted by Berg himself from Frank Wedekind's plays Erdgeist (Earth Spirit, 1895) and Die BÃ 1\/4 chse der Pandora (Pandora's Box, 1904).
Simplified: Berg took the story from two plays called Erdgeist and Die BÃ 1\/4 chse des Pandora by the German playwright Frank Wedekind. Berg wrote the libretto (the words for the opera) himself.