In the evenings in the Chinese city of Hangzhou, friends meet to "throw eggs" -- a card game winning fans despite official warnings that it is an addictive waste of time and a drain on productivity.
Played since the 1960s in the eastern provinces of Anhui and Jiangsu, Guandan's popularity has skyrocketed in recent years, becoming a national sensation.
Local media estimated that over 140 million people are hooked on its combination of strategic acumen and social fun.
"When we play, we do it while drinking tea, chatting and playing all at the same time," said 60-year-old Tang Songyuan.
Tang was so enthralled with his new pastime that he opened a clubhouse in Hangzhou in October.
His 20th-floor space offers its hundred members the chance to "throw eggs" to their hearts' content, with some playing rooms overlooking the city's shimmering business district.
The relatively simple game pits two teams of two against each other in a race to shed their cards by throwing various combinations referred to as "bombs" -- a homonym of "egg" -- on the table.
"It's a very healthy game that everyone can take part in together," said Qiu Zining, a middle-aged woman who joined Tang's Hangzhou club a month ago.
"It's super fun, with very strong participation and interest, so I also became fascinated by it."
- 'Poison bomb' -
But Guandan is not winning all hearts.
This month, the state-backed Beijing Youth Daily warned that an "addiction to 'throwing eggs' has become a social phenomenon deserving of attention and vigilance".
Other Beijing-backed media condemned it as "decadent" and "escapist" -- a drain on productivity at a time when China's stalling economic recovery needs all the help it can get.
A few years earlier, Beijing had issued similar criticisms about the phenomenon of "lying flat", referring to young people rejecting the rat race of urban living for a simpler, less professionally ambitious life.
In response, President Xi Jinping called for them to "eat bitterness", an expression meaning to endure hardship, as youth unemployment became a key drag on China's economy.
Official concerns over Guandan's popularity also reflect the Chinese leader's longstanding efforts to stamp out alleged waste and laziness among public sector employees.
State media has derided the game as a "poison bomb" that "corrupts the work style of officials".
- 'I'm enjoying my life' -
At Tang's Hangzhou clubhouse, members have kept "throwing eggs".
The facility hosts competitions twice a week, as well as regular training camps, giving its members an opportunity to put their skills to the test.
Tang showed AFP his club's inventory of Guandan equipment, including playing tables with dedicated zones for "throwing eggs", automated card dealers and plastic "pass cards" deployed by players who want to skip their turn.
Guandan can also be played on a phone, but Tang maintains that digital versions are no substitute for the real thing.
"One of the more important attributes of Guandan is that it has social interaction," he said.
"If you play it on your phone, you lose this."
Player Qiu shrugged off the censure from state media.
"Me playing (Guandan) is a small action, right? I will not affect anything at the national level," she said.
"I am enjoying my life through a common hobby with my friends, being together and enjoying life."