Saber Interactive is introducing a new difficulty setting to zombie-ridden co-operative action game World War Z, turning the challenge up to the extreme. The free "Six Skulls" will force players to manage their resources, think strategically and work with their friends (or AI pals) to get through each campaign chapter, and there'll be unique rewards available for those who accept the challenge.
This follows the last patch, "The Undead Sea" which opened up a new mission aboard a spooky ghost ship (or zombie ship, in all reality). Saber Interactive also plans on releasing a new weekly challenge mode, new weapon variants, character skins and accessories in a free update in the near future, however, no release date has been revealed.