If you’re a fan of lit RPGs, then you don’t need to read any further. This is one of the best.
For those who are not, well, all I can say is use this book as your jumping in point. It doesn’t take itself too seriously, and the mechanics are in-depth and intetesting while also not taking away from the plot.
Please do yourself (and the author, who is independently publushed) a favor and pick this book up.