I (an American with a lot of interest in China) was playing doudizhu with some Chinese friends recently. It was agreed that the losers would have to kowtow to the winner instead of paying money. I was on the losing side and it meant nothing to me, while even in a private, joking setting it was apparently a very uncomfortable thing to have to do for my teammate. See also the general cultural attitude toward doing something embarrassing as a "punishment" for losing a bet or game, something fairly unknown in the US.