The Trollium strongbox is the opposite of the Fortunium and Neptunium strongbox. It has a 0% chance of dropping red/black gear, black keys, elite cores, as well as any weapon/armor that comes after level 40. It has a guaranteed chance to drop 0*** normal gear. Any Steel-Neodymium strongbox has a 1% chance of being turned into a Trollium strongbox. If you are playing nightmare mode with 3 or more people on your team using High roller, the chance of a Trollium box will be knocked down to 0.5%.