Unite union members at Auckland's SkyCity have walked off the job as part of their campaign for better pay.
Some workers have begun picketing the casino after rejecting a pay offer of four to six percent for most staff.
Strike action began at 6pm today.
The union's advocate, Mike Treen, said the the union's members deserved a living wage.
"We have an offer that is still $1.50 less than the living wage ... We think that is just not adequate and it's 3 percent behind inflation so it's actually a wage cut."
Treen said staff who have worked at SkyCity since it opened were paid the same hourly rate as new employees doing the same job.
SkyCity said it was disappointed in the strike action by employees.
A spokesperson said SkyCity has brought forward wage increases for non-union employees from 1 December to 1 August.
The spokesperson said fulltime staff on individual employment agreements will, on average, receive an extra $1200 this year.
The union said hundreds of workers would join the strike action, however, SkyCity said only 22 had walked off the job.
The spokesperson says other changes for staff on individual employment agreements include a one-year service hourly rate equivalent to the September 2022 Living Wage.