In the tram/bus, tapping a debit or credit card purchases a single-ride ticket.

Regarding public transport, you may find the mobile app Jakdojade (Jakdojade’s website) very helpful! It’s avaliable in English. Jakdojade not only will help you plan your journey (trains, trams, busses) but it is also possible to buy tickets with this app. We highly recommend you to buy a 72H ticket as it will allow you to travel everywhere around Gdańsk, at any time of day and however often you need during 3 days. It is also possible to buy tickets in red ticket machines that may be found near most tram/bus stations. Here is map of the ticket machines.

WARNING:  bus /tram drivers do not sell you tickets.