The Plaguelands is intended to be an end game farming system which you have to use Corruption to enter and is a way to obtain super rare items compared to usual.

The Plaguelands can be accessed through the Portal UI on Nightmare, Hell, and Torment difficulties and unlocks after clearing Stage 1-10 of each difficulty.
You will need 30 Contamination to enter the Plaguelands which is consumed the longer the stay within the zone. Contamination will recharge over time whilst you are online or offline so you can save up and make a push for higher grade items are your own leisure.
Chests will drop less frequently here but will have a much higher chance of ultra-high grade items than in normal zones (Celestial or higher). These chests will be stored separately to chests obtained from the normal area available before this update.
There will also be the ability to apply a Plague Intensity to the Plaguelands before entering which will make it more difficult but increases the rewards as a result.
Once you reach a Plague Intensity of 6 or higher there will be a chance of dropping Contaminated Soulstones that can be used to face off against Contaminated Bosses that are harder than normal bosses with even greater rewards.
