Must I secure permission from a publisher to write a novel based on characters in a book I read 30 years ago?

The publisher that you submit to is not the one who decides. You would have to get permission from the author of those books you mentioned or the benefactor of their estate if they're not alive. You don't need permission to use those characters' names, but the characters themselves are copyrighted. It's best not to use characters from other books. There are way too many legal problems that can arise from it. Publishers aren't likely to risk fighting a court battle for a new author. I suggest changing the characters enough so that they do not resemble the characters from those other books.

Getting published is very difficult. Don't make it harder for yourself by bringing a ton of legal baggage to the table on the first day.

As the copyright laws can vary greatly depending upon when the book was published (for recent- after 1971- books, the copyright won't elapse for 95 years!), your best bet and best advise would be to write to the publisher to get permission to use those characters in a novel you are writing. It is possible- but not likely- that your book is in public domain, and the only way you will know for sure would be to either write to the publisher or hire an attorney to do a Library of Congress record check- and guess which one is cheaper.

First, a copyright lasts 70 to 90 years. If there was a subsequent edition, the copyright would extend from that date. Copyrights do not have to be registered, and they can will willed to descendents. The "legal" proof of copyright exists by the mere fact the book has already been published.

You can certainly write a book "based on" characters and stories previously written, but I wouldn't use character names.

Even if you do nothing wrong, you should prepare for a grandchild to possibly file a lawsuit which would be costly for you to defend. Such is our litigious society.

The honest truth here? You won't get published as a teenager. And this isn't me saying this to shoot you down, but I've heard of such teens on this forum wanting the same thing. And the chances of you getting accepted are somewhere in the same realm as winning the Mega Lottery on a $1 ticket by itself. Traditional publishing? You have a 1 in 900,000 shot at being taken in by a reputable publisher if you were much older and more experienced. Even still, it is a long shot. But as a fellow writer, I'm glad to see that what you're writing IS original. For awhile there, I thought I was the only one doing it still--seeing how everyone else is content in being a mainstay copycat. :0)

I would contact the publisher that originally published the book. If nothing else, they will know who to contact regarding the copyright information (the author, the author's estate, etc.). Generally, it will depend on exactly HOW you are drawing on those characters, but I doubt that they will say no to most things. It all just depends. Contact the publisher for now and they will likely lead you in the right direction.f

My understanding (and I'm certainly no lawyer) is that you need to contact the author. The book is definitely still under copyright so using substantial portions of the book (which it sounds like you would be doing) would be illegal unless you got the author's permission. If you aren't using a substantial portion then you could try to claim that your use of the characters falls under fair use but fair use is so ill-defined that that's subject to the whims of the court system.

Copyrights last for 21 years. They must be renewed. Check the government web site and see if the book is into another printing or if the copyright has been updated.

see a publisher

probably

usually its a 100 year rule or something like that

Bill Clinton. And do not stick him where the sun dont shine with daptomycin or his booty may get toxic.