tarotbear
To tell you the truth - as long as you are not 'redrawing' images from movies or production stills from plays - and you are creating 'your own' drawings of characters you are not breaking any copyright rules that I can think of... a woman in a 1930s evening gown can be any woman in a 1930s evening gown until you tell us that is (whoever). If you used the Hollywood or television casts of 'Death on the Nile' for inspiration - yes - that would infringe on the people that designed the costumes, sets, the actors that played them .... etc.
However - wanting to use the name 'Agatha Christie' is what will give you the problems... you may have to get permission or even pay a royalty to her estate to use her name ... legally. Her name would be the 'drawing point' for the sale of the decks.
However - wanting to use the name 'Agatha Christie' is what will give you the problems... you may have to get permission or even pay a royalty to her estate to use her name ... legally. Her name would be the 'drawing point' for the sale of the decks.