Every night this week, Mari Vanna has locked its doors promptly at 6 p.m. Show up after that and though you can peer through the front window to see revelers toasting with vodka shots as a strolling accordionist plays peppy Russian songs, there's no obvious way to get inside. Jiggle the door handle a few times and you might catch the attention of a tall blonde hostess, who cracks the door and asks, "Do you have a key?"

Mari Vanna gives regulars keys to the front door, so they can let themselves in whenever they want. (Photo by Josh Reiss)

The popular Russian restaurant and lounge south of Dupont Circle hasn't quite turned into a private club, but it changed its entrance policy as of Monday night. After 6 p.m., there are two ways to get in: Use a front door key, which Mari Vanna staff distribute to regulars, or press one of the 10 doorbells next to the door and hope that you've picked the one that rings inside, attracting the attention of a host.

It seems strange that a restaurant would adopt a confusing and seemingly exclusionary entrance policy with so many restaurants feeling the pinch from the ongoing government shutdown, but Mari Vanna founding partner Tatiana Brunetti says that's not the intention. "Within a year, all Mari Vanna locations lock their doors at 6 p.m. every night," she explained in an e-mail. "This isn't meant to keep people out -- on the contrary, we want visitors to feel as though they are guests in our home. We want diners to start their night at Mari Vanna the same way they might at a friend's house. What's the first thing you do when you arrive for a dinner party? Ring the doorbell and receive a warm welcome."

The other option is the front door key, which Mari Vanna has been distributing to VIPs and regulars on custom matryoshka keychains since its January opening. Bartenders and managers have a stock of the keys, which they hand out to familiar faces. The added bonus is that regulars can use their keys to gain access to a weekly party in the third floor lounge – formerly "Key Mondays," now "Key Thursdays" – with a DJ and plenty of vodka shots.

Mari Vanna isn't the only restaurant in town to make guests jump through hoops to enter. The Gibson, Heist and PX rely on unmarked doors; entering the Sidecar lounge below P.J. Clarke's requires swiping a membership card; and the Flash dance club on Florida Avenue has a secret entrance in a photo booth. But Mari Vanna is trying to be egalitarian.

In the interest of disclosure, I was given a key before the restaurant opened in January, but a bartender offered me one on a subsequent visit after we chatted about pairing vodka and Baltika beers. Brunetti says that anyone is eligible for a key if they "keep showing up." She writes: "Come to happy hour, come to dinner or try your luck at Key Thursdays. If you stop by more than twice, we consider you a regular deserving of a key to our heart."

Happy hour's the best and cheapest way to start: From 5 to 7 p.m. on weekdays, house-infused vodka shots are $4 instead of $8, cocktails are $7 instead of $12, and selected appetizers are half-price. Stop in a few times and you may be given a key and invited back for Wednesday's late-night karaoke sessions.