First mentioned in chapter 1615.
Primordial Divine Ruins tested players' survivability rather than their Basic Attributes and combat standards. They were similar to Regional Dungeons, only far more dangerous.
But danger and opportunity stood hand-in-hand. Primordial Divine Ruins offered far more treasures than elsewhere, and even the loot in super-large-scale Team Dungeons paled in comparison. Combat techniques, in particular, didn't drop in Team Dungeons.
Among the many players that had grasped combat techniques in the past, a large majority had learned their techniques from the Primordial Battlefield. In fact, 80% of the Advanced Combat Techniques players had learned had originated from the Primordial Battlefield.
Primordial Divine Ruins were similar to Team Dungeons as only a limited number of players could enter the ruins at a time. The number of players allowed to enter the ruins depended on the ruin's size, which could range from several thousand to several tens of thousands. On top of that, Primordial Divine Ruins only opened once a day.