It’s hard to be specific without knowing what this is about, so I will invent an example (with some mild borrowing from dragon age).
Let’s say your world has religious views about the use of blood magic, and one of the standpoints is that blood magic is evil and shall never be used. Most player characters won’t be such hardliners, but since the narrative exists in the world, some will be, especially if they have been shown bad users of blood magic.
Now, let’s say that later in the book, you realize that what might have been a side plot mcguffin, has suddenly become important and cool. That mcguffin is a magical item powered by people’s blood. Your story suddenly hinges on the fact that the protagonist uses this mcguffin, it will be so much better if they do! For most, no issues. The advantages of using the mcguffin will make most players use it, but for the ones thinking blood magic is evil, they would not.
Opps. So how to solve this without changing the world? There are a few ways.
1: Establish early on that the protagonist is not a hardliner. Yes, that might mean going back and adjusting text and choices. They can still be against blood magic, because it is easy to be abuse, but make sure to write in some leeway and doubts in the choices and dialog. Take a moment to figure out why the character would hate blood magic, and make sure that’s not in a way that gets in the way of using the mcguffin. Maybe blood magic is evil because it allows for controlling people, or using their blood for your ends. The mcguffin uses the wielder’s blood, and doesn’t control people. This might give you an opening for some internal thoughts why it would be okay to use for the hesitant.
2: The greater evil. Establish something worse than blood magic. Maybe a massive arch demon is taking over the world, and can only be stopped by the mcguffin. Just make sure that you give the sacrifice of the character’s morals the weight it deserves. Not a choice made lightly.
3: Flexible morals. Allow people to justify their decisions in the game. People do this all the time in real life. As long as it’s internally consistent, you can get away with a lot.
No matter what tactic you pick, the MOST IMPORTANT thing is to NOT give a choice whether to use the mcguffin or not. The choice you give is how you justify using it, and for people who might be against it, you need to make sure that the seeds for those motivations are planted through the story.
Hope that helps.