| I've done two trips to Gusgen Mines for skulls...I've NEVER seen them drop...plus, the Ghouls there (particularly the scythe-wielding ones) are far stronger than the ones roaming around Valkurm Dunes.
For skulls, I would highly recommend the NW oasis in Dunes since you can get as many as 4 Ghoul spawns on a good night, and hopefully you'll get at least ONE skull from them. However, there are an alarming number of the mid-level Goblins there (Leecher/Mugger/Gambler), and I've noticed that an Earth Elemental will spawn every Firesday, which can be quite bad for magic-users since the Elemental will be drawn to their spells.
Personally, I'm either going to wait until my 30s before skull-hunting again, or I'm going to coerce some of the buddies I met at Dunes to help me get my skull (which shouldn't take too long since most of them got theirs already).  "With everything going wrong, George W. Bush did what ANY of us would do...he went on vacation." |