Yesterday, I took a train from Zurich to Engelberg, and bought a ticket from a ticket machine at the station for the journey. I was running a bit late for the train, so there wasn't time to queue up to ask for advice, I just had time to put the machine into English, tell it where I wanted to go, and pay for the return.
On the way there, there was a ticket check on both trains. Based on those around me, I appeared to be the only person with a regular paper train ticket! Everyone else had either a credit card sized card they showed, or a card with a long ticket, or an A4 printout, or a pass.
That made me think that perhaps there were railcards / rail passes / special tickets / etc that I could perhaps have bought instead, if I'd only known about them....
For someone who's only going to Switzerland for a few days, what railcards / rail passes / etc should you be aware of, to investigate if they'll save money?