The phrase in question refers to sexually explicit or pornographic material featuring characters or elements from the science fiction video game, “Beyond the Skies.” The term “rule 34” is an internet adage stating that if something exists, pornography of it exists. This adage is then applied to the aforementioned game.
The existence and prevalence of this type of content are indicative of the intersection between fan culture and the widespread availability of explicit material online. The relative popularity or volume of such content related to a specific property can be a (though not always reliable) gauge of a property’s overall reach and engagement within online communities. Historically, the creation and distribution of such content existed in more niche circles before the advent of widespread internet access; now, it can spread rapidly and become a significant part of a property’s online footprint.