Lucky's $500 Plaque - The Legend of Dragon Gate
There are actually several sets of meaning you can derive from this plaque, so take it as you will. Ultimately, fish = good luck.
1) The Legend of Dragon Gate 鲤鱼跳龙门 (lǐ yú tiào lóng mén)
https://en.wikipedia.org/wiki/Longmen_(mythology)
This very well-known Chinese mythology of Dragon Gate tells the story of thousands of Koi/Carp fish swimming upstream together in the Yellow River against a strong current. They eventually reached a huge waterfall where most Koi turned around and gave up. However, a few Koi persevered for hundreds of years and eventually managed to jump across the waterfall (symbolized by the dragon gate) where the gods rewarded them by transforming them into a majestic dragon, symbol of power and ascension.
Historically, this myth was a direct metaphor for the Imperial Examination system in ancient China. For centuries, the grueling national exams were the only way for a commoner to transcend their social class and enter the scholar-official elite. Against impossible odds, to succeed is to "become a dragon," moving from a life of poverty and obscurity to one of great power and prestige.
This phrase remains relevant to this day, where over 13 million students participate in the annual gaokao exams with less than 5% gaining admission to the top 100 universities.
Or, as in the case of poker, to succeed in tournament play against impossible odds in a field of thousands.
2) Every Year an Overflowing Abundance 年年有余 (nián nián yǒu yú)
https://baike.baidu.com/en/item/Surplus Every Year/50071
The auspicious idiom wishes you a life of abundance and surplus wealth and is often said at Spring Festival. The character 余(yú) "abundance" is a homophone of the character 鱼(yú) "fish," hence the symbolism of using an abundance of koi/carp.
In Chinatown, you will often see Chinese restaurants with huge fish tanks on display, stocked with plenty of fish swimming around inside. This idiom is the meaning behind it.
3) 9 Koi Fish
There are a total of 9 fish: 8 in the river plus the 1 gold one in the foreground.
The number nine symbolizes eternity, fullness, divine blessings, and long-term wealth in Chinese numerology, as it represents the pinnacle of harmony and the emperor's power. This configuration draws from ancient beliefs where the eight colorful koi generate positive energy (qi) for abundance. Eight itself evokes "prosperity" via phonetic similarity to "wealth" (fā), while the ninth black koi acts as a guardian, absorbing sha chi (bad energy) to safeguard the fortune.