Up to 95 publicly-funded theatres across England will offer free tickets to young adults in a government-funded scheme.
From next year until 2011, the theatres will offer free tickets - at least one day each week - to 18 to 26-year-olds on a first-come, first-served basis.
Theatres including London's National Theatre and the Birmingham Rep will be eligible to apply for the scheme.
Culture secretary Andy Burnham denied the scheme was a "gimmick".
The scheme follows recommendations made in a recent government review about engaging young people.
The Supporting Excellence in the Arts report, by former Edinburgh International Festival director Sir Brian McMaster, recommended a "free week" to engage young audiences by opening up publicly-funded arts organisations.
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