Yeah, it's a rapidly expanding an evolving genre with its own conventions and quite a bit of influence from Chinese webnovels and anime. Your average litrpg usually involves a System Apocalypse or an Isekai Protagonist.
System Apocalypse - God like Magical Computer "System" that tracks peoples stats/skills, recognises their feats and rewards them arrives on earth and integrates the world into "The System" usually in the form of a magical cli gui that appears in peoples vision as they go about their day.
Isekai - Average person going about their business dies in an accident and is reincarnated on another (magical) world with memories of their past life intact.
System Apocalypse - God like Magical Computer "System" that tracks peoples stats/skills, recognises their feats and rewards them arrives on earth and integrates the world into "The System" usually in the form of a magical cli gui that appears in peoples vision as they go about their day.
Isekai - Average person going about their business dies in an accident and is reincarnated on another (magical) world with memories of their past life intact.