It's really, really obnoxious. I have the achievement, but it took 10+ trips to one delve (the 2nd or 3rd to last one I needed to clear), and each visit I cleared the boss I didn't need 5-10 times...

Certainly not a fun one. Still better than fishing.

Are you killing the other bosses? Bosses only spawn if one is dead, and since the same boss can spawn twice or three times, you need to keep circling the delve and killing the bosses that are up until the one you want spawns.

It's one of the most frustrating aspects of the game.

Yep, did that achievement on 5 characters and sometimes it's annoying as hell. The worst are actually those with 3 bosses. There are 2 deep in AD territory which are particularly obnoxious: Boodymane Cave and Pothole Caverns. The respawn timer is set to 10 minutes for both and that means it takes at least 20 minutes to clear them. You can actually see exactly when 10 minutes pass if you look in your character window at the Blessing of War buff: +20% AP gain after killing a delve boss (some addons will show that in UI). When that buff goes down to 50 minutes is time to check the spawn locations. The boss that spawns is actually random, but only one can spawn at a given time. But the respawn timer is not uniform. For example Toadstool Hollow, between Bleakers and Bruma, has 5 bosses but they spawn every 5 minutes so it sometimes takes less time to clear than the ones mentioned above. One thing they should do is to make the respawn timer uniform in all delves, and slightly decrease it to 3 minutes, which is also the cooldown for getting loot out of a dungeon boss.

DoctorESO wrote: »

Boss respawn is horrible indeed. Whose great idea was that, anyway? Please don't let them make the next DLC.

The one responsable for this mechanic is also responable for fixing the lag issues in Cyrodill ;