2 Henry IV has a particularly troubled publication history. As a history play, it was subject more than most to censorship and revision by hands other than Shakespeare's. The play was first printed in quarto in 1600. It appeared again in 1623 in the collection known as the First Folio. There are many discrepancies between the two versions.
Modern printings pick and choose from both, presenting a combination of both texts.
This study guide uses the New Folger Library edition of the play, printed by Washington Square Press.