They aren't dropping in some places...its a bug. Grind dolmens, they're dropping there. I hope this helps, good luck!

I didnt get one in Lions den (even if I make loads of damage (as my main dd in a group together with the low level alt of my husband) ) and I got loot from the boss. and one boss I got a skull the other I didnt (my husband got one from each.

There is a lot of false information in this thread. The final boss of every dolmen, the one that drops after the 4 pinions are closed and molag bal taunts you, is a boss and should drop a skull. Even the little small anchors that drop 2 waves of enemies count. There is a cooldown of 3-5 minutes between drops.

When you compete with 5 thousand other people at each dolmen for the next week good luck getting anything

Go to Cryodiil, do the dolmans there. You'll find less competition there.

I killed four bosses in the Grahtwood public dungeon; they all dropped set gear, but only one of them dropped a plunder scull. I don't know if that was because there is a cool down on the plunder scull drops or if something else is afoot.

Only problem with arena is you can beat the boss prior to the cool down timer being over

Avoid the crowds. Find stuff that's solo or quiet too

Reading the notes there is a cool down period if farming same boss or bosses

gpkreutzerub17_ESO wrote: »

have been running dark anchors in Deshaan and have only gotten 1 skull in five completions.

I do dungeons 3 skulls each dungeon

I like the plunder drops ...but I also like leveling an alt. Seems a waste to get non level cp160 drops.

From what I can tell for plunder skulls dropping or reasons why extras drop I've done testing and pretty sure I have found reasons why for either of them.
For why you could not be getting plunder skulls at a dolmen is too many people and either that or someone is doing kill steals and making it harder for others to get it. Also another factor is you are not doing enough damage as well.
As for why there can be extra plunder skulls is if a boss spot has more than one boss at and you have them split up far enough distance in groups and kill them separately. One group will have a skull as long as you pick it up further away from the other so you don't pick up the skull and it to be counted for both. Then pick up the other and you have two within seconds of each other.
Now there are ways people can steal kills and make it so that you don't get any loot.

jlboozer wrote: »

They aren't dropping in some places...its a bug. Grind dolmens, they're dropping there. I hope this helps, good luck!

Dark anchors and dolmens are the same thing.

....also, don't overlook the little mini-dolmens...when the daedrics materialize randomly, in 2 groups of 3 each, you will get plunder skulls from them as well...the main monster of the 2nd group is a boss... it's a little bit more work, and totally random, but you'll be certain to get the skull, unless you're near a regular dolmen & the entire zerg swoops in on ya <g>