Understudy, Swing, Standby: What's the Difference?

Short Answer

An understudy usually holds a regular onstage role and also covers other larger roles; a swing and a standby are both off-stage, with a swing covering ensemble roles and a standby covering a lead, according to StageAgent. Broadway.com instead groups standbys and swings together as covers for lead roles. Sources define these terms slightly differently.

Checked October 2026 against Broadway.com and StageAgent.

What Is an Understudy?

Broadway.com describes a principal as "the listed performer for a lead role." StageAgent describes an understudy as "a performing member of the ensemble, who covers other larger roles, perhaps even the lead." Broadway.com describes the role in similar terms: understudies are "usually part of the show in a non-leading role but may be called upon to step into a lead role." Both descriptions agree that an understudy already has a part in the show before stepping into a bigger one.

What Is a Swing?

A swing, by StageAgent's definition, is "an off-stage cast member who covers multiple, if not all, of the ensemble roles." Broadway.com describes the role differently, grouping swings with standbys as performers who "can cover one or more lead roles and only perform in them when required." The two sources do not agree on whether a swing covers ensemble roles or lead roles.

What Is a Standby?

StageAgent defines a standby as "usually someone in an off-stage position who covers the lead role or roles and is NOT part of the ensemble."

How You Will Know a Cast Change Happened

The guide to Broadway Playbills explains how a cast change is traditionally announced: a small slip of paper inserted into the Playbill before curtain. Under a 2025 agreement between the Broadway League and Actors' Equity Association, some productions can now use a QR code instead, along with a verbal announcement or a posted cast list. That guide also describes the cast list itself as "organized by role with understudies and standbys noted."

FAQ

Does every show have an understudy, a swing, and a standby?

Not necessarily. StageAgent notes that "some shows only have understudies, not standbys." Which roles a production uses can vary from show to show.

Sources

• Broadway.com, "What is the difference between a principal, understudy, standby, and swing?"
• StageAgent, "Understudy, Standby, Swing!"
• TheatreShelf, Broadway Playbills