|“||When you're ready to explore the Hazardous Ruins, prepare enough stamina and health items for the trip. Good weapons and equipment are also crucial!||„|
|— Loading screen tip|
The Hazardous Ruins are ruins from the Age of Corruption that are dotted throughout the land, now populated with hostile monsters that have taken residence in the dangerous environments. They offer rare treasure chests, loot, crafting materials, and other items for tough explorers to plunder, but are closed off to the public until given special clearance. The Civil Corps is responsible for investigating the safety of and allowing access to Hazardous Ruins.
Portia has several Hazardous Ruins. The Sewage Plant, Ingall's Mine, and Deepest Ruin are the only ruins that can be accessed at will, and have maps that are randomly generated (with the exception of the final floor of each level, which is the same every visit). The ruins that are part of main missions aren't revisitable outside of their missions, like the WOW Industries sewage system and Computer Lab Ruin.
Every ruin has multiple levels, and each level spans across multiple floors. Each level entered costs a set amount of time to enter, meaning that time inside the ruins freezes and more time is not consumed while within the level or when advancing to the next floor.
Most floors must be cleared of all enemies to advance, though some floors simply require navigating through obstacles to reach the next floor. The final floor of each level features a boss that must be defeated to complete the level. Treasure chests and/or smashable Wooden Crates can be found on most floors.
The player has maximum amount of three attempts, or lives, to complete a level, though the player also has the option to quit at any time in the middle of a level to return to the overworld. If the player fails all three attempts, then they will be kicked out of the ruin and lose their level progress. [ verify ]
Portian Hazardous Ruins
|“||I have been ruin diving for years, and the hazardous ruins around Portia have been some of the most interesting that I've seen.||„|
|— Male Tourist|
- Main article: Sewage Plant
The toxic Sewage Plant ruins are located past in the northeast inner city of Portia, gated off within the Collapsed Wasteland. This Hazardous Ruin features many toxic enemies, noxious gas jets, and green, acidic water that causes damage for every second of contact.
- Main article: Ingall's Mine
Ingall's Mine is an abandoned mine in the Eufaula Desert, overtaken by various giant sand worms as well as humanoid miners that are no longer considered human.
The instance of Ingall's Mine that is visited during Rescue in Ingall's Mine can only be visited once, during that mission. The instances that the player visits later will always be randomized, besides the boss floor of each level.
- Main article: Deepest Ruin
The Deepest Ruin is a late-game ruin in the Somber Marsh, spanning across dozens of floors. Many rare materials, including Carbon Fiber, Military Engines, and Compressors can be obtained here, as well as the powerful sword Macuahuitl.
Up to 19 levels can be completed per day.