Fan Casting Related Differently in the Adaptation in Sort by Tropes

Two or more characters belong to the same family in a given story. This story is then adapted into a new work and while these characters are still presented as being related, exactly how they're related differs from the original. This could be done for a few different reasons. The creators may want to explore a different relationship dynamic between the characters or add a certain plotline that works better if their relation to each other is tweaked, such as by adding Half-Sibling Angst, an Archnemesis Dad, and so forth. Or maybe they want to simplify things by merging multiple characters into one, or trim certain details out of pragmatism if it doesn't affect the plot or characters significantly (for example, it's easier to establish that "Bob is Alice's brother" rather than having to explain he's actually "her second cousin-once-removed who was raised by her parents and so they're Like Brother and Sister anyway"). In the case of some stories, such as myths and legends, it may not even be entirely clear which version of a family tree is correct or regarded as 'canon', so the creators of the adaptation have to choose whichever one they feel fits best. A subtrope of Adaptation Relationship Overhaul and can overlap with Adaptational Upbringing Change. If the change results in a character moving forwards or backwards a few generations, it could result in an Age Lift too. It may also result in an Adaptation Name Change, especially in regards to surnames. See also Related in the Adaptation, Unrelated in the Adaptation and Promoted to Love Interest.