It is an expression intended to bring good fortune to stage performers.
But as staff at Diss Corn Hall stayed true to the theatrical superstition, the last thing they expected was for pantomime dame Peter Brad-Leigh to quite literally "break a leg".
Mr Brad-Leigh had been preparing to assume various guises, including Widow Twankey, in 'The Magic of Panto', a three-person show written by Jeremy Bond from JezO's Events.
But while dress rehearsals are usually a good time to get slips and trips out of the way, the dame didn't even make opening night after toppling over in a pair of stilettos.
"Coming off the stage, Peter just misjudged the steps," said Lee Johnson, operations manager at the Corn Hall. "I think when you are wearing a big frock, it does obstruct your view somewhat.
"At first we thought it was a twisted ankle, but when it started to swell we knew it wasn't good. We had quite literally said 'break a leg' beforehand."
At hospital it was confirmed Mr Brad-Leigh had broken his fibula, rendering him unable to take part in the 13-performance run.
But his fellow actors, Mr Bond and Emily-Grace Fox, from LP Creatives, proclaimed "the show must go on" and set about re-shaping the script in a single night.
Having begun welcoming audiences on Saturday (December 19), the panto - with its reduced cast - has proved a resounding hit.
And Mr Johnson said it was proof the arts sector can adapt in a world changed by coronavirus.
"People really seem to be enjoying coming to the theatre," he added. "The audience has been fantastic and they are relishing every moment.
"Everybody is socially distanced and they are saying it doesn't make any difference to their experience. People have been able to forget, just for a moment, that we are in the middle of a pandemic."
After securing funding from Arts Council England, the Corn Hall recently launched its Act Now initiative - the first step in creating a producing theatre company based at the theatre.
In partnership with established director, Emma Bernard, the venue will host regular workshops from January, culminating in a performance in March.
To find out more, email actnow@thecornhall.co.uk or call the box office on 01379 652241.
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