There is a bug doing this quest (Tactical Observations), when collecting the restless bone marrows. The giants in Kael only give them to you if someone is on that part of the quest. I failed the combine and spent hours trying to get more after and not one dropped. This is very frustrating. Please help resolve this issue.
This was not true, but there's always the possibility it was changed. While working the mercenary and partisan quests in Kael, the bone marrows dropped. I looked it up to see that they would be needed for a future earring quest, so my normal group started collecting them. By the time we were ready to start the 6th earring quest, all 5 members of the group already had 6 bone marrows each, and we had let some rot. Four of us made the earring on the first try, while the 5th failed the combine and lost the marrows. We were able to go back to farm enough for him. That said, the marrows are rare at worst, uncommon at best. I've gone long stretches without seeing any drop, and then I've seen 3 drop in 10 to 20 kills. They also can drop from the trash mobs in the mission, but I don't know if the drop rate is the same. I just happened to notice when I was going for the collection set that drops there.
Unless specifically changed that isn't true. Ngreth had previously stated a drop rate of 5%. Keep killing.
I just did 5 earrings the week of labor day. I specifically leveled the previous earrings in kael to get enough marrow for all 5 toons. Took me somewhere in the neighborhood of 4k kills to get about 50 of the restless marrows combined for the team. I personally killed in a loop around the arena and outside the arena (was doing hunter at the same time). That said, the skulls for the quest DO require you to be on the quest to get them to drop, but the marrows most definitely are (or at least were a month~ago) prelootable.
As said above, its just an abysmal drop rate, but they do drop all the time regardless of quest status. Farming the mission trash seems to drop a bit more often than the static zone, but still very uncommon. I went to the mission to get the ones I needed because static zone was just too frustrating, clear drop and repeat.
