It's a fantasy role-playing game.

DM: You are Scanlan Shorthalt, a gnome bard . You are the member of the famous group of adventurers. Previously, They stumbled upon a small hive of basilisks that surrounded an obelisk of Ioun, which gave them their first clue as to the location where this sphinx could be found. They battled the basilisks, destroyed their underground hive, or at least the exit from it, via Fireballs and Stone Walls and other such endeavors.
DM: And coast down and you land harshly, taking three points of damage in your crow form as you hit and land and tumble down a few stairs.
Player: Ooh, stairs.
DM: At that point, you're in complete darkness right now, you can see a faint distant bit of light that's barely creeping in from the entrance you came from. Around you, though, nothing.
Player: I'll break form and come back as Scanlan.
DM: Okay. You come back as a gnome. Now your darkvision kicks in and indeed you can see there is a smoothly carved tunnel overhead that descends down a long flight of stairs. Make a perception check.
Player: Natural 18.
DM: And you have 60-foot darkvision? As a gnome?
Player: It just says darkvision. I didn't write down the distance.
DM: Okay, I'm going to look this up real fast. Because this is important to know for this circumstance.
