The Bird in Hand in Stafford has introduced a Covid referee system to ensure that those in attendance follow the rules and regulations around face coverings and social distancing.
The system involves a yellow card for a warning, then a red card for any further breaches of the rules, meaning the customer will be told to leave the premises and banned from coming back.
The card system was the invention of landlords Terry and Dee Cope and has so far seen 150 customers banned since the pub reopened in April.
Mr Cope said he had come up with the idea, which involves blowing a whistle at people breaking the rules, during the period after the first lockdown last year.
He said: "I've had these cards in the pub since we moved here four years ago and we've occasionally used them as a bit of a joke, but also with a serious side to it.
"We weren't getting people's attention when we were telling them to sit down and put masks on, so I got the whistle, which really makes a sound.
"Most of the customers are football fans, so they get the concept and when the whistle gets blown, everyone shuts up and waits to see who's been carded."
Mr Cope said the reaction by a lot of people to being carded had been shock, but the majority of his customers had understood and supported the system.
He also said that he had enforced the rules to protect customers, as well as his business.
He said: "I will walk up to people and say that they've had enough warnings and my staff are not going to put up with it and we're not there to be Covid police.
"They have to understand that they are putting our lives and other peoples lives in jeopardy, as well as my licence, as if we're not seen to be abiding by the rules, we could get shut down."
Mr Cope said the system would remain in place for when the pub is allowed to open indoors, with people given a rundown of the rules when they come into the pub.