Grimrock

You guys must of done something else since there is no way this is only connected to the Nex sword.

Wouldnt open for me, went down to level 7, walked back up the stairs, went to the fighter's challenge door, it opened. Thats all you have to do.

obviously not. I've been to floor 9 and the door will still not open.

I'm all the way to the inner sanctum, and I have the NEX sword equipped, but it still won't open

I've been pretty diligent about looking for secrets, I'm not sure what I need to do...

If you're having trouble opening the door, make sure nothing is on the ground in front of it, walk back up the stairs, then back down, and move in front of the door. it might open. It did for me at least. No idea why, but I tried everything mentioned in the thread and nothing worked.

I had a torch on the ground, but after picking it up and going up/down the stairs, the door magically opened. I didn't have the Sword of Nex equipped either. I had the Dismantler equipped, but I doubt that has anything to do with it. Also I was level 10. Maybe it was a glitch? Hell if I know.

Hope this helps.

Ok I confirm: the opening of the gate is related to the Sword of Nex.

I tried to drop the sword before stepping in front of the gate, and it didn't open. I picked up the sword, equipped it and walked toward the door again, and it opened!

Note: after a few tries, i confirm that you don't even have to equip it, just having it in your inventory is ok.

I think ayon is on to something and this may actually be a bug as a torch being on the ground (which is on the ground for me) seems like a silly reason for the door not to open. Thanks man I'll try it again now.

Confirmed, if there is a torch on the ground it won't open even with the NEX sword.

Oh my god! You found it!
I had a discarded piece of armor on the ground. I picked it up, walked back and forth the stairs, and bingo, the door opened!

So, there is three possible restrictions to open the door:
-You must have visited lvl 7 once. It seems to be the most common thing said by players and walktroughs.
-You must have the Sword of Nex. No need to be equipped, just in inventory. Need confirmation, but its a pretty recuring answer too.
-You must NOT have any item on the ground in front of the door! This is 100% sure, just tested it.

As I said earlier, the "must have sword of Nex in your inventory" is confirmed. I ran some tests and it's definitely a requirement.