In the case of the Belgian cartoonist Herge (or rather his estate), the answer is not very well.
The Comics Reporter and Artnet reported last week that the Herge estate has lost an important copyright lawsuit over Tintin, the famous Belgian cartoon character. The estate had sued a Netherlands-based Tintin fan club in 2012 over its use of the original copyrighted images in newsletters sent out to club members. The estate sued the club in a Belgian court, and after three years of legal wrangling the judge ruled in favor of the club.
And here's where things get interesting.
The fan club won the case not because of fair use (as I would expect) or because the estate didn't own the copyright (it still did). The estate lost this case after lawyers working for the fan club found and submitted an old contract which showed that Herge had assigned the publishing rights to his publisher in 1942. The court has ruled that 73-year-old contract was still valid, casting a legal shadow on all rights contracts for Tintin.
It's not clear to this blogger which rights were assigned nor if the estate still controls some rights. You can find the ruling here (PDF). I'm not an IP lawyer and I don't read the language, so I will leave the specific details to the experts.
Between the book rights, movie and tv rights, and most importantly the merchandising rights, the Tintin decision just upset contracts worth millions of dollars a year - no joke.
This is a replay of the 2013 court battle over the ebook rights to Julie of the Wolves, only on a much larger scale. In that earlier case two publishers (HarperCollins and Open Road Media) disagreed over the digital rights to Jean Craighead George’s bestselling children’s book. The case hinged on the point of whether the original 40-year-old contract included ebook rights even though ebooks did not exist at the time and were only mentioned tangentially.
Open Road Media, which had secured the digital rights from the author in 2011, said no. HarperCollins disagreed, and the larger publisher ultimately prevailed.
It's impossible to say how the Tintin copyright situation will play out, but it promises to be both messy and remunerative for IP lawyers.
Since most authors can't afford the costs of a legal battle, they would be well advised to opt for an ounce of prevention and learn what rights they are signing over before putting pen to paper.