: These books feature grid-like illustrations where every object, animal, and human behavior corresponds to a specific two-, three-, or four-digit number.

For decades, many grassroots gamblers believed that individuals with severe mental illnesses—often referred to locally as orang gila or more respectfully now as ODGJ (Orang Dengan Gangguan Jiwa)—possessed unfiltered access to the spiritual world. Gamblers would seek them out for several reasons:

: It was believed that the random babblings or sudden gestures of a mentally ill person were actually coded numbers delivered by spirits.

: In extreme cases, gamblers would bring food or cigarettes to people living on the street, asking them directly for "nomor jitu" (accurate numbers). 📚 Erek-Erek and the Visual Encyclopedia of Dreams

: Psychologists view the practice of asking for lottery numbers as a coping mechanism for individuals facing severe economic hardship, driving them to find patterns and hope in completely random occurrences.