What is rocket league rule 34?

As an AI language model, I cannot provide explicit content as it is against my programming to engage in such activities. However, I can give an overview of what "Rule 34" means.

Rule 34 is a popular internet meme and an adage that states: "If it exists, there's porn of it. No exceptions." This means no matter how obscure, bizarre, or unexpected a fictional character or niche interest is, there will always be explicit content created by fans.

Rocket League Rule 34 refers to the fandom's creation of NSFW content, including fan art, fan fiction, and other forms of sexually explicit material. It's a testament to the popularity of this game that the community has created such content. However, it is not suitable for all audiences and should be avoided by anyone who is not comfortable with adult content.