Like a lot of rules, enforcement needs to be realistic, appropriate and not overly harsh. In Oslo at least, the obvious tourists tend to get let off with just

Like a lot of rules, enforcement needs to be realistic, appropriate and not overly harsh. In Oslo at least, the obvious tourists tend to get let off with just buying a ticket, even though the ticket app makes it easy to buy the correct ticket. If you speak Norwegian they often look at your travel history to see if you’re a regular payer who just forgot.