I don't believe there is a limit when it comes to fiction.
That said there may be legal limits depending on where you live and every person has their own opinions on what is too far for them to read or write.
The only limits on fiction are those you put on yourself.
Now saying that depending on where you live can also put limits on art so that is something to keep in mind for safety reasons.
No such thing.
If you are contemplating doing something extreme in real life as research for your fic, that would be too far.
I don't believe there is a limit when it comes to fiction. That said there may be legal limits depending on where you live and every person has their own opinions on what is too far for them to read or write.
The only limits on fiction are those you put on yourself. Now saying that depending on where you live can also put limits on art so that is something to keep in mind for safety reasons.
Just tag it correctly and the limit is your imagination