Disease

Diseases on Avlis require a +50% higher Save than the Bioware originals.

For example: The DC to thwart the least impressive diseases, such as Filth Fever, has climbed from 12 to 18. At the other extreme, you will need to beat a DC of 38 rather than 25, to survive the Soldier Shakes.

You can check the original DCs on the NWN Wiki.