BlackSithis: Aren't the puzzles in that room random? I thought the game checked your inventory and created the four puzzles according to stuff you have. Otherwise, it could create a situation where it's impossible to advance. I'm surprised to see that's actually the case.
But if you don't have that trait, you most likely won't have any skull and going back to find one (not even remembering where one is) is a game killer, I think.
Edit: ah, I see I necroed this thread. Sorry about that ^_^'
SpiderFighter: Sorry, I didn't see this post until now :)
No, that puzzle is not random (I don't think any puzzles are). While it's not impossible to advance, it does mean you'll have to backtrack if you don't have the four items you'll need. There's a skull on level 8 in the Herder room (lower left corner of the map - the portal to enter is at the end of the hall in the lower right corner of the map). And, yeah, it kinda sucks to go back, but I guess it's more realistic than having the game hand it to you.
Get some health pots ready - you'll need them!
Yeah, but first you have to decipher the riddles, then either place the items or go look for them. Having to track back through empty dungeons to search for an item you don't even know is the right one is very frustrating. More so when some of the items are class/trait exclusive (I had a few arrows with me because I'm a bit of a hoarder, my only rogue was actually a dagger user). I was lucky to have all four items (plus the one to open the iron door), but do I feel sorry for those who weren't :/ It punishes you, not for your lack of wit, nor your lack of dexterity, but for not having the right class/trait. The item to open the iron door doesn't bother me too much. It's a bonus, so it's fine to be harder and the item itself... well the fact that it apparently does nothing should raise suspicion enough to keep carrying it around with you.
I've already finished the game, good thing I was saving on those tar beads :D And apart from that puzzle, I really loved this game. Will definitely play again sometime in the near future, on hard mode, with a different team and this time I'll get all those damned doors! Missed three of them, eight secrets and one frustrating Toorum letter (that moment when you realise you just found the last of the letters and you only have 15 :( )
Edit: no, really, that first door that I missed is still bugging me. I spent so much time trying to find the answer, just looking at that freaking area that I ran out of food and had to do the next couple of levels relying only on crystals and potions to restore my health/energy. And I had food, LOTS of it. At times, in the wee hours of the night, I go outside to the balcony for a cig, and this is what I think about! IT'S KILLING ME!
Disclaimer: I won't say which level it was for fear of spoilers, no matter how well-intentioned they may be. I'm going to find the answer on my own, it's the only thing that matters to me now. I will conquer that mocking door! Also, I'm embarrassed by how easy it probably is.