firestore.rules

rules_version = '2';

service cloud.firestore {
    match /databases/{database}/documents {
        match /cities/{city} {
            allow read: if request.auth.uid != null;
        }

        match /characters/{character} {
            allow read: if request.auth.uid != null;
        }

        match /users/{userId}/{document=**} {
            allow read, write: if request.auth.uid == userId;
        }
    }
}