The high priests, @, are the head of all religious activities related to the deities. There are exactly four in the game: three corresponding to each of the deities of the player's pantheon (who appear in the High Temples on the Astral Plane) and the high priest of Moloch (who appears in Moloch's Sanctum). Additional high priests may appear if an aligned priest gains experience. As with aligned priests, they are generated with a mace, small shield, and one of a robe, cloak of protection, or cloak of magic resistance.
The high priest of Moloch holds the Amulet of Yendor, and it is extremely likely that killing him will be necessary in order to obtain the Amulet. This can be difficult, and players will tend to save a wand of death charge for the specific purpose of killing him; this will not work if he is generated with a cloak of magic resistance. He turns hostile once you step into the room holding the High Altar of Moloch, so be prepared before opening the door.
The high priests on the Astral Plane are always generated peaceful, and will remain that way unless you attack them.
It is possible to determine the alignment of each high priest by calling it a name ("The high priest of [god] doesn't like being called names!"). You can do this as soon as you arrive on the Astral Plane, if you have telepathy. Because this method eliminates the need to find the correct high altar by the process of elimination, it is considered by some as cheating. This is also known to players as the Astral call bug. It occurs because high priests are strangely enough considered unique monsters, despite the fact that there will always be at least four of them in a complete game.