In ancient times, our ancestors counted the years with 10 celestial stems and 12 terrestrial branches. Although this was scientific, most people were illiterate and could not memorize or calculate easily. Thus the animals that influenced people’s lives were chosen to symbolize the terrestrial branches: the rat, ox, tiger, rabbit, dragon, snake, horse, sheep, monkey, rooster, dog and pig.

Not all luck-bringing papers are couplets. Some are four-character-phrases that express traditional sentiments for a rich and bountiful spring. Still others are single characters, for example, the Chinese character "fu(福)".

Posting the "福" (pinyin: fú; jyutping: fuk1) character is a tradition for Chinese people during Spring Festival each year. "福" is difficult to translate into English; it means something like "幸福" (xìngfú; happiness, blessing, well-being, being satisfied with one's life) and "福气" (fúqì; good luck, good fortune). Posting the "福" character represents people's wish for a good life and happy future.

The "福" character is often posted upside-down. It is said that this is because the character for "upside-down", "倒" (pinyin: dào; jyutping: dou3), is a homonym of the character for "to arrive", "到" (pinyin: dào; jyutping: dou3). So this means that "福" (happiness, good fortune, etc.) is "arriving".

Here comes three legends of the origin of Upside-down "Fu" Character

  
In ancient China, people considered the kylin (qí lín 麒麟), the phoenix (fèng huáng 凤凰), the tortoise (wū guī 乌龟) and the dragon (long 龙) as sagacious animals, and called them the "Four Deities"(sì líng 四灵) as the symbol of auspice. In fact, besides the tortoise, the other three are legendary animals created by ancient Chinese.