As TheAsh says, there are significant differences between the movie and the book:
- Gate and key challenges are completely different
- The Grail Hall with the librarian does not exist in the book
- The final scene with the egg is about 50% different
- Characters die in the book that do not in the movie
- Interactions between the characters are different (Meeting, friendship, etc)
- Ogden Morrow's involvement is different between book and movie
- Some of the backstory behind Halliday is different
- Ancillary character involvement is different
There are more, but that is probably enough to demonstrate that they are almost completely separate entities. I would say that there is at least 75% difference between the movie and tbe book, which would be enough to warrant the suggestion
Yes, we need two tags. The movie and book are very dissimilar.
I would suggest the following guidelines:
- ready-player-one - For questions about the book, that can only be answered by a book reference (Such as a question about Zork). Example question: In Ready Player One, how was Wade Owen Watts able to complete a perfect game of Pac-Man in his first try when it usually takes years to do?
- ready-player-one-2018 - For questions about the movie, that can only be answered with a movie reference, such as this question (Since the race is only in the movie), How often did the race occur in Ready Player One?
- If a question can be answered by either the movie or the book, tag with both. One possible example is Dying after completing part of the challenge, as it could potentially be answered in two different ways, one via movie and one via the book.
As a secondary corroboration for the need of separate tags, is that it was not easy to find a question among the (currently) 26 questions that might be answerable by either. There really is very little crossover between the movie and the book.