How does AppleCare+ work on an AppleWatch?

I was thinking on purchasing AppleCare+ for my new apple watch, but seeing that there is a service fee for screen replacement? I was just wonder how much it generally requires in Melbourne?

Do scratches on the screen count as 'accidental damage'? And more practically, what other benefits do we usually have for getting applecare+?

Cheers

[Re-Titled by Moderator]