Have you played games? Do you know what the main quest is? You can understand playing coins this way.

(The main and side quests are separated)

Do you know traditional Chinese medicine? Do you know what observation, listening, questioning, and pulse-taking are? You can understand playing coins this way.

Palmistry, character measurement, facial reading, Zhouyi, Five Elements, and Eight Trigrams, when applied to humans, cannot be separated from the four characters below!

(Checking appearance and reading colors) It's not the milk tea you drink!