Once you have set your pin and it has been confirmed when you log onto Runescape and attempt to access your bank account you will be asked for you pin and you will enter it via a clicking the numbers of your pin on a number pad. This number pad will rearrange itself after each click. The Runescape bank account pin system was setup up like this to prevent Runescape hackers gaining your secret bank pin via a key logging mechanism or a click tracker because the numbers are never in the same position twice.