How big should the playing field be in Unity?

Question

Game development

What size should such a playing field be? How to choose the right size in general?
This is an example from the book Unity in action, where they make a small first-person shooter, but there is not much said about this. The question arose due to the fact that there will be a field of at least 1000x1000, at least 50x50, the difference is not particularly noticeable. Or is it about proportions?

Answer 1

Usually 1 unnamed unit in Unity is taken as 1 meter, that is, the character will be about two units high, and so on. In the end, it's just convenient. And if you change the scale a lot, you will have to tweak the camera settings, and physics on large scales and speeds can behave strangely.