Riders
- They were to have met in the garden of the Chapelle Expiatoire at five o'clock in the afternoon, but Julio Desnoyers with the impatience of a lover who hopes to advance the moment of meeting by presenting himself before the appointed time, arrived a half hour earlier.
So opens The Four Horsemen of the Apocalypse by Vicente Blasco Ibanez, as translated from Spanish to English by Charlotte Brewster Jordan. The book is in the public domain; you can read it at Google Books. Since the mention of the four horsemen in the Bible, they have appeared in many other places: in the book quoted above, in the books' various motion film versions, and also in roguelike games including ToME and NetHack.
Three of the horsemen, Death, Famine and Pestilence, appear in NetHack at the Astral Plane. We often call them The Riders, despite that that they are merely major demons who are not riding anything. Then where is the fourth horseman, War?
You are War
You are War. You descended through the Mazes of Menace and retrieved the Amulet of Yendor, in the process massacring large numbers of monsters (or hiring pets to do it). You made War on the dungeon, seized the Amulet, left the dungeon for the Elemental Planes. Now, with your arrival on Astral, and the imminent #offering of the Amulet, all four Riders meet, and it feels like the world is about to end.
In the game, only Death, Famine and Pestilence are named. However, if you #chat to Death, you are told, "Who do you think you are, War?", though the punctuation is ambiguous. But the comment in monst.c#line2741 is definately not ambiguous:
/* Riders -- the Four Horsemen of the Apocalypse ("War" == player)
*/
Strategy
Of the three riders, Pestilence is widely considered to be the most dangerous. Hence a common Astral Plane strategy is to identify which altar is guarded by Pestilence using telepathy, and then explore that altar last.
Teleportation has a special effect on riders: if they are zapped with a wand of teleportation, they are teleported to a square adjacent to you. This is a very bad idea.
All riders come back to life; after 12 turns, a rider corpse has a 1/3 chance of revival on each turn[1]. The only way to permanently banish them is to kill them, then fill every square on the level with monsters so that when they revive, there is nowhere for them to go. You know a Rider has disappeared when you get the message "You feel less hassled"[2].
By the way, eating their corpses doesn't get rid of them either; it gets rid of you quite effectively, though. A YASD for the ages, to be sure.
