Kind of old fashioned now that almost every Unix system is a single user system. There are still public servers for those that want the temptation to be taken away from them.
As to spoilers... Everybody reads the spoilers. I doubt anyone has ever ascended spoiler-free.
A friend once showed me a post on rec.games.roguelike.nethack where someone was finally begging for a hint because they'd gone deep in the dungeon and couldn't figure out anything to do next. They couldn't find any staircases down, though they had found a weird vibrating square, and none of the many weird items they'd collected seemed to do anything to help.
On DOS, the ! Command, gave you access to the levels files, for which you could make a closet level.
I always started a few rounds as every role, and watched the hilarity begin with the stupid ways to kill yourself, which after a few months, were always hillariously fun to read.