This phrase refers to a category of online content that features a character from the Dragon Ball franchise, Android 18, depicted in sexually explicit or suggestive situations. The term “rule 34” is an internet adage stating that if something exists, there is pornography of it. In this context, it means that the character has been the subject of adult-oriented fan-created material.
The prevalence of this type of content underscores the widespread popularity of the Dragon Ball series and its characters. The existence of such material is indicative of the broad reach of fan art and derivative works that often accompany popular media franchises. The production of this type of content is also driven by the anonymity afforded by the internet, and varying societal attitudes towards depictions of sexuality.