how do I open the Duke Nukem room in Jojo's Circus? I know where it is and I've reached it before but for some stupid reason I can't open the door now. TNT doesn't work on the wall either and I've tried all the panels behind the snake pool where the door is.

I'm so glad Dusty fielded this one.
I was about to tell you it was a sector trigger thing, and that you had to run around the snake pit area until you heard a timed sliding door, followed by you having to race to get to it.

That's what happens when you take b1 advice from a b2 guy.

=[

well, the door will close after a few seconds, so you can't really lollygag around and expect it to still be open. =]P

edit:spelling

thank you. Now I need some help to get to house of horrors. what combination is the key picture switch over the broken bridge meant to be to reach the secret level?

Play around and see.

Not helpful at all. >:(
Tell me something useful or don't bother trying to help. playing around brute-forcing the buttons is very tedious and its what turned me off one or two of the Duke 3D levels: combination button locks and no fucking clues to solve them. even if there is a clue to the Blood lock, I can't be arsed to track it down.

I think the combination you need is in the Jojo area with the snake pit, on a banner on one of the walls. I forget what it is exactly. If you have a save game near the exit, just go view the combination, then reload the save game.

Sorry if I appeared rude. But this is how I found out the right combination at least. By just button mashing.
AFAIK there's no hint anywhere about the correct combo.

I had no idea there was actually a hint for the combo...

Thank you very much. The level itself is meant to be some kind of ghost train/log flume from what I've seen after using the hint. its only a conveyor belt with a water texture though as Calab takes fall damage if you jump the gap in the unfinished tube. Its OK. its just many good older shooter communities especially Marathon tend to force players to discover hidden secrets on their own after revealing only hard to get or understand stuff e.g. "what does the hidden computer say in the third to last level of Marathon 2? find it and see. *trollface*" that is what pisses me off so I was a bit blind to the fact that more people than I thought genuinely didn't know. Even the Blood wiki is unclear on reaching that one level. its still a big problem for Duke 3D though as the button puzzles there have no hints as far as I know. the missile code on Area 51 is the worst offender. similar frustrations are Marathon 1's elevator stairs puzzle on Colony Ship for Sale, Cheap, or all of Wolfenstein 3Ds level design. (mainly because Wolf3D has no automap and ROTT Dark War's map looks like arse and is hard to read.)

I didn't know that. I figured the combination out because that's the order in which you acquire those keys in the level.
Then again, I stumbled into the entrance to the secret level by sheer dumb luck. Didn't even know it was there.

Keen observation on your part. The first time I did it, I just look at the keys I had in the inventory and mash 'em until the thing went down, I would always forget the order though. Years later some one mentioned the banner and I could finally visualize it and remember the order.