The itempropdef.2da file is the .2da file that defines the types of item properties that are available in the game. Many of the rows in this file have hardcoded effects, so the customization possibilities (for those rows) may be limited. SubTypeResRef: The .2da file named in the "SubTypeResRef" column must have a "Name" column that contains a StringRef for the name of the subtype, and should have a "Label" column for the reference of human readers. Whether or not other columns are required depends on the particular item property type (row in itempropdef.2da).