A little over 12 hours earlier a gunman massacred 58 people from his room on the 32nd floor of the hotel, however, and the bonhomie at the Rock and Roll Denim bar may be a little forced.
But gamers at the hotel -- scene of the worst mass gun killing in modern American history -- are in no mood to be cowed by the startling and sudden outburst of violence, insisting they will keep gambling.
Father-of-two Bill Cook, from New York, checked into the Mandalay Bay for a conference several hours before Stephen Paddock opened fire on an open-air country music festival opposite the hotel.
"I'm trying to take my mind off what happened. I feel terrible for the people who were involved and my thoughts and prayers are with them and their families," the 48-year-old computing systems engineer told AFP on the gaming floor.
"But I've just got to keep moving on. If I dwell on it then I'll just be afraid forever."
Cook, whose room was facing in a different direction from the festival venue where the tragedy unfolded, says he was first made aware that something was wrong when the organizers of his conference sent out a cell phone alert.
He told AFP a SWAT team went from room to room at about 3.00 am (1000 GMT) checking guests were unhurt in the attack.
"I think they did a good job getting the situation under control," Cook said. "It is scary but there's a lot of things happening in the world. If you let everything affect you, you're always going to be hiding out in a corner."
Although he intends to see out his stay, Cook says he was with a friend from New York who had been worse affected by the night's events.
"He was two floors above the shooter and he's heading home. He heard everything, he could see everything," Cook told AFP.
Veronica Haig, from Round Rock, central Texas, joined her husband, Robert, another conference delegate, at the Mandalay Bay and was planning to make a holiday of it.
"It was really just crazy. However, this morning you come in here, it's completely somber and I'm just in awe of everyone that's here... I've been thanking a lot of people for coming to work today," the 42-year-old mother-of-two told AFP.
Haig recalled hearing sirens and helicopters shortly after the violence erupted, and going to her window to see the commotion below.
"I was thinking, 'Wow these windows are really thin. You can hear everything.' My husband was already in bed. I went downstairs and that's when they said, 'We're on lockdown -- don't leave, don't go anywhere, go back to your room, lock the door.
"I went back upstairs, turned on the television and saw what was going on and it was just crazy that something like that could happen, that so many people were hurt."
Haig said she had no intention of cutting her trip short, however.
"Right now we're going to stay here. Maybe we can have a little fun. Maybe."
Joanice Green, smoking a cigarette and hunched over a Hexbreaker 2 fruit machine, was visibly shaken by the attack but stoic in her reaction.
"There are going to be crazies everywhere. It can happen anywhere at any time, and it can happen in your own back yard," said the 45-year-old San Francisco Bay Area resident.
"So that's not going to stop me doing what I need to do, for the reasons that I came here. But it's very sad. I think I spent most of last night in tears, just knowing that people down there were hurt."
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)