Once a PC hits level 10, Armored Defense (without Improved Armored Defense) will only calculate correctly if the armor bonus to Ref is 0 or 1. Once the PC hits level 20, it will also calculate correctly if the armor bonus to Ref is 0, 1, or 2. And if you put in level 30, it's good for an armor bonus of 0-3.
Once a PC hits level 10, Armored Defense (without Improved Armored Defense) will only calculate correctly if the armor bonus to Ref is 0 or 1. Once the PC hits level 20, it will also calculate correctly if the armor bonus to Ref is 0, 1, or 2. And if you put in level 30, it's good for an armor bonus of 0-3.