A granite stairway is a dungeon feature present on every floor of the IVAN dungeons, connecting your current floor with the dungeon levels above or below you. There is also another way of travelling between floors: through magic portals found in the Dark Level and Lower Gloomy Caves. Both staircases and magic portals are indestructible.
Usually there are two staircases per level, one upstairs and one downstairs. Each staircase is usable in both directions and the two staircases on a dungeon level are always connected by a walkable path.
You can ascend or descend any stairs with the "<" and ">" commands. If there is a pet in your line of sight while you're using the stairs, it will follow you, but the same applies to hostile monsters. While you will always land on the next stairs, your pets and enemies will be placed in the nearest unoccupied space.
While the vanilla game has only linear dungeons with no branches, most of the variants add some branches to the main dungeons, be it Kharaz-Arad from LIVAN or Dragon Caves from IVANT. Subsequently, there are additional staircases on the branching floors, providing you with an access to the side dungeons.