[MandieD]

In Nürnberg, you can either buy paper tickets from ubiquitous automats or in the local transit app (with a pre-configured credit card or current account). I love it.

Local bus drivers will sell tickets, but there are also ticket validation machines in the middle of most busses. Local trains and subways are trust basis, but I've seen more random ticket checks recently. Ticket checks are more frequent on long-distance trains, but still, no barriers. I have yet to travel on local or long-distance trains in Germany or Austria that aren't trust-based.