Citizenship from French step-parent?

[blake_sturges]

I've seen a lot of posts talking about how one can attain French/EU citizenship from a French national parent, but does this still qualify for a French step-parent? None have specified or even mentioned a difference between step-parents and biological parents. My step-father was born in France and recently immigrated to the US, (I am American) marrying my mother a few years ago.
I am still a minor, currently 17 years old. Would I somehow qualify for French citizenship through him? Would he need to legally "adopt" me? Would there be any tests?
Thanks,
Blake

[obormot]

My memory is that the child can be adopted in "complete" (not "simple") form and then get french citizenship as if by birth, but the child has to be at most 15 (or, at least, your have to start to live with you step-father before 16). So if he married your mother and started to live with you when you were 15 or less, then he might still be able to do it, but it has to be done before you are 20. It is called "adoption plénière".
Here (let your step-father read it):
https://www.service-public.fr/particuli ... oits/F1094
https://www.service-public.fr/particuli ... oits/F3070
Note that adoption plénière means many things for your step-father and for you. In particular, France has funny inheritance law and laws of supporting ageing parents..