An inventor in southwest China is gambling that one of his ideas will cut the cost and equipment involved in playing mahjong. Chongqing advertising designer Wang Kai says he has come up with a pack of mahjong cards that is lighter and cheaper than the traditional tile version of the game, the Chongqing Morning Post reports. Wang said he was a fan of the game and hit on the idea while going to mahjong houses to play. He said the houses were always crowded and players had to pay a fee to sit down at a table. With the cards, he said, any group of four people could get together in almost any place to play a game for free. The cards were easy to carry and could help players save money, Wang was quoted as saying. He said the online version of the game was also popular but the virtual environment did not help people spend time together as a family or friends. Wang said he had patented his card idea and already turned down a 500,000 yuan (US$72,500) offer to buy the rights, the report said.