Well, 'rdr' might stand for a number of things. Maybe it's a code name, or an inside joke among fans or creators. In the context of 'pulp fiction', which is known for its complex and often cryptic elements, 'rdr' could be a clue to a deeper meaning or a hidden storyline. However, without more information, it's really just speculation.
The main distinction of porn with a story genre from regular porn is the presence of a coherent narrative. Regular porn often jumps straight to the sexual action, while the story genre tries to add some kind of story framework around it. But in the end, both are adult-oriented and feature explicit sexual content.
Well, it's hard to say for sure. The concept of 'porn-like' is quite subjective. Some might consider certain novels with excessive sexual descriptions as such, but it depends on individual perspectives and cultural standards.
In many places, 18+ porn comics are considered illegal. This is because they can have a negative impact on society and violate moral and legal standards.
In RDR2, you might find crime novels in various places. One common place is in the houses or buildings around the game world. Sometimes, they can be found on desks or bookshelves in the homes of more educated or wealthy characters. Another possibility is in certain shops or stores in the towns. Keep an eye out for any book - related items during your exploration.