Many cities have travel passes catered for tourists who want to see as many things as they can within 2 to 3 days. If that’s you, get those because you’re probably going to get a bang for your buck, plus discounted entry to some sights and attractions.
But if you’re like me and prefer to travel slowly and spend a week or two in a city/town/village, you’re better off getting a local travel pass. In London this is the Oyster card, in Dublin it’s the Leap card. In KL, it makes no difference.
Typically, you’re charged a lower rate per trip and passes are often accepted on all public transport including the tube, rail, buses and trams.
These cards also have a cap on how much you can be charged per day and a little bit of math will tell you if this is a better option than what the Visitor Information Centre is suggesting you buy.
A general rule of thumb is that a local travel pass is worth the hassle if you’re spending more than 7 days at a destination. Most travel passes last up to 7 days long anyway.
Before leaving, some destinations offer a refund on your card i.e. you get paid in cash the balance on your travel card and/or you return the pass and get back the initial €X you first paid for it.
When in doubt, ask your hostel receptionist or check it out in Google.