This can be seen on the PTE where despite many wipe/resets over the years it's seen by the system as being the same world and players only get a badge for the first time they killed the fortress. I've got multiple accounts that have PTE badges and most of them have been involved in first place killings as well so some in 2nd and 3rd and even 4th place. No badges are gained if one already exists for the PTE even though it is new start. (This is the nature of the PTE and is the result of adopting most (but not all) of the settings from the production worlds.
