Selling games based on Public Domain material?

Recently I had some ideas, but I decided to find out if they are worth developing as my goal is to make a shareware prodcut.
Say, I decide to make a game which follows on of public domain movies (Try Night of the Living Dead, Carnival of Souls, Nosferatu etc.), could I sell them? What if I credit original authors? Does that mean I get into any financial obligations?
What if a movie has a remake (Like with NOTLD or Nosferatu)?
I know in theory it all should be fine, but have anyone else though about it?

What?

You would have to stick to material which was in the original and be 100% sure you didn't use ANYTHING which was introduced in the remake.

http://www.openflix.com/

www.archive.org

They are believe me... Nosferatu obviously is more that 75 years old, and NOTLD was never copyrighted! That's why George A. Romero is not a millionaire despite all the "Night of the Living Dead at midnoght" thing... Sad really...

Yes, sorry. I checked before posting and realized my mistake. Just forgot to edit my reply after checking, lol.

Just to be clear though. You do need to make SURE that these are truly PD. Just because people believe they are doesn't mean it's 100% true. There are a lot of urban myths widely believed.

EG: Ship's captains can marry people, Woodstock was held at Woodstock. Lots of things. Copyright is even worse.

I know... The film I'm actually interested is "The Cabinet of Dr. Caligari" which was made in 1920-s, so the copyright had obviously expired... It had a remake of sorts in 60-s called "The Cabinet of Caligari" and a fan remake (a very impressive one I might add) in 2005.
NOTLD is officialy PD since I've seen quite a lot of interviews about it (It's one of those very unfortunate copyright stories where the prodcut is getting recognized, making some money domestically and overseas, spawns a cult, but the filmmaker isn't getting a penny).

Then you need to be very careful not to reference anything from either the sequel or the remake. Ask Jake ( GreyAlien ) about the copyright situation for Wizard of Oz for an explanation of how complicated that can be. One example which springs to mind is that the book had no mention of Ruby Slippers, it was an invention of the movie studios who wanted to find something to show off their new technicolor technology. The book featured silver slippers instead. That's the kind of fine detail you would have to check if you wanted to do that.

I think it's a pretty cool idea BTW. I suspect there is some really great material in there.

Yeah I can confirm the slippers thing. If the producer had used anything from the movie we'd have been stuffed.

Anyway, sounds like a cool idea, I never knew about OpenFlix!

so......... I could make a game of "Troy", and as long as I make sure that it takes longer than a week to defeat the city, and make Achileses Mum older then him Id be ok copyright wise? (Or am I getting mixed up with Alexandra)

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