Police said the men entered the Rugby Union Club in Turner about 12.40am Sunday. One man was holding a bat and another a large machete.

The trio made threatening demands to the club's staff members, ordering one employee to lie on the floor and a second employee to open a safe.

When the safe did not open the second employee was guided to the poker machine room and ordered to open the machines. The men stole a sum of cash and fled.

The first man is described as about 178cm tall. He was wearing a black facemask, a thick blue jacket and black tracksuit pants.

The second man is described as about 188cm tall. He was wearing a balaclava, black tracksuit pants with white stripes down both legs, and white sneakers.

The third man was wearing black clothing.

Club general manager Jeremy Wilcox said his "concern at the moment is with the welfare of our staff". He did not comment on the robbery.

ACT Policing is seeking CCTV footage from the area and investigations are ongoing.

Police have urged anyone with information about the robbery to contact Crime Stoppers on 1800 333 000 or at act.crimestoppers.com.au and quote the reference number 5807130.

Information can be provided anonymously.