The First Descendant players have discovered a Destiny-style loot cave but, rather than 'simply nerfing certain content', the devs are leaning in and making every cave a loot cave

pcgamer.com:

In the early stages of Destiny, the original game and not the sequel, players made a wonderful discovery. There was a cave in the Old Russia area of the open world where some sort of glitch made enemies respawn constantly, with higher drop rates than usual. Destiny being Destiny, word soon spread, and the cave would be constantly encamped by multiple player groups, annihilating anything that poked its head out, and watching the colourful little loot globs scatter everywhere. You'd sit there shooting for minutes on end, then gleefully go on a little rat-run through the firing zone, engrams endlessly flowing into your guardian.

If you ask me, Destiny never got better. The loot cave persisted for a short while before Bungie inevitably nerfed it, though it was so beloved that the developer also inserted an Easter egg where once it stood.

Nexon's new looter-shooter The First Descendant launched earlier this month and, you guessed it, has arrived complete with a loot cave. In this case it's more of a loot outpost, I suppose, with the exploit called the Valby Run and located within The Fortress area. Mobs at this location have been respawning infinitely and at high speed, whereas most other outposts will eventually run out of enemies, and slaughtering them en masse will drop a boatload of the game's resources: gold, kuiper and the all-important gear loot.

So all hail the Valby Run. The development team have now addressed this issue, and perhaps not in the manner expected.

It rather goes without saying, but the Valby Run exploit «was certainly not intended,» said Minseok Joo, director of The First Descendant. «Due to our systematic mistake, Mobs at the Fortress Outpost have been respawning infinitely. And as a result, the amount of item drop has increased 2-3 times higher than that of other popular locations.»

Joo says that «to be adored by our players for a long time, we believe that it is wrong to just look on and leave the unbalanced content, which is providing biased