I ran into a recent account of a game that, as I understand it, the DM decided by himself was going to be a vampire campaign and as I understand it told some players but not all of them. It seems a good example of how game worlds actually work.
One player utterly resists and fights back against the vampire, utterly resisting being turned. Everyone else is turned.
People are cross with the player. But he was clueless to the overall agenda and played his character not wanting to be made into a vampire, as characters are wont to do.
The thing is if he had been talked with and told it was a vampire campaign and that his PC would be turned – well, he’d either agree to this premise or not play (or something)
His character might still not want to be turned, but if the player agreed he will be turned then the player would at some point stop giving game world physical reasons that would stop the turning. Eventually the player would cave in and accept the vampire has him pinned enough to turn him – not because the PC is somehow definitely pinned by game world physics, but because the player agreed to being pinned and turned at some point.
Without agreement, he’s struggling and his PC is trying all sorts of physical moves to avoid being turned. With agreement he gets turned eventually.
The difference between them isn’t game world physics, it’s what players agree to (with agreement sometimes being on a spectrum sometimes)