AC-apply is a property of armor type equipment.
Equipment that gives "armor by -X" exists, but players will mostly get their AC from armor equipment through AC-apply. It is important for beginning players and is still useful at higher levels.
The following paragraph is quoted from Nilgiri creation primer by Mobius.
- The location of objects when they are of type armor also have an AC-multiplier. Objects of type armor have a value setting for how much is subtracted from the wearer's armor class. The AC-multipler is multipled by by the armor's value for a total number that is subtracted. For example, if the armor value is 3 and the AC-multiplier is 2, the total number that is subject from the wearer's armor class would be 6. However, if the armor value is 5 and the AC-multipler is 0, the overall number subtracted from the armor class is 0.
Table of AC-multiplier values
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