Time: June 24, 2015 around 7:00 PM PST
Frequency: Only once
World name: Coeurl
Character name: Kinedel Manedel
NPC name: N/A
Class/level: Scholar/55
Party or solo: Party, 4 people
Steps:
1. Unlock a new dungeon. In my case, I had unlocked The Aery the night before, but did not enter nor clear it.
2. Sign up for "Duty Roulette: Low Level".
3. Accept the team once the duty finder is ready.
4. You may end up in a dungeon you have unlocked, but have not yet cleared.

This behavior appears to be inconsistent with "Duty Roulette: High Level" and "Duty Roulette: Trials" which requires you to complete duties before you can randomly end up in them via the roulettes. Roulettes appear to fill the purpose of rewarding players for re-running previously cleared content to potentially help fill in gaps in teams trying to complete content for the first time by allowing the server to select duties for players in the roulettes. In my case, I was running the low level roulette for the daily bonus and to pass the time while I wait for my friends to log in and be ready to clear the Aery together. Because my friends and I had agreed to enter the dungeon together to experience it for the first time, I felt cheated of that experience by this behavior from the low level roulette. Due to this, I soon chose to abandon the duty so that I could continue to wait for my friends.