下次一定xià cì yí dìng

Someone asks you for something, and you do not want to say no. You say 下次一定, and both of you know the next time will not come. The joke is how polite and how empty the promise is.

Now it works anywhere. A friend wants you to go running at 6 a.m., a shop wants you to fill in a survey: 下次一定. Said with a smile, it is a soft no. Said to your boss, it can sound like you are not serious.

It comes from Bilibili, the video site. At the end of a video, creators ask for a 一键三连, a “one-click triple”: a like, a coin and a favorite in one tap. Bilibili uses these numbers to rank videos. Coins are scarce, because a normal user gets one a day for logging in, so many viewers answered with 下次一定.

Nobody has found the first comment, and accounts of who typed it first differ. By December 2020 it was so common that, when Bilibili named its 弹幕 of the year, a popular comment pointed out that 下次一定 was missing from the list. A 2022 article on Bilibili coins described screens full of the line every time a creator asked for coins.