Copyright law is complicated, but unless the author has been dead for at least 70 years you should expect to pay Performance Royalties

You must also have prior permission from the author or their agent, and you should not assume that because a Play has been published that it's therefore available for performance

And unless you're performing in a private home or a classroom, a Performance Royalty will be due whether or not the Play is performed in whole or in part, whether or not it's for charity, and whether or not the audience pays admission

Photocopying scripts without permission is also a breach of copyright

Details of how and where to apply for Performance Rights are invariably printed inside the Play