Depends on whether you enter it solo, in an incomplete party or a complete party.

By design it should help fill queues where they are needed. If there are twelve players queueing, nine for roulette and three for individual dungeons, technically every player queueing for roulette should be sent to one specific dungeon chosen by the players that queued for specific dungeons. If they did queue for sastasha, tam-tara and toto-rak...sucks. All nine players will get the hated dungeons.

If there is no one queueing for a dungeon that can be accessed by everyone in the party that entered a roulette (or if the party is pre-made), it should be completely random. Same if everyone is paired from a roulette.

This is only speculation based on the purpose of the roulette though. And it's pretty reasonable to expect something along those lines...with obvious mess-ups due to computer random not being random (and most random generators are low-effort ones that are even less random than that).


As for "it shouldn't be like that"...it should. It's a roulette. At the end of the dungeon you receive experience bonus to "match" the highest level dungeon, so you're not losing on experience (but are on drops and sucks if you don't finish it for some reason). Don't want random?! Then queue for a dungeon specifically. You will get similar experience from the highest available dungeon run normally as you would from a roulette with a bonus.