lv1 20
lv2 22
lv3 24
lv4 26
lv5 28
lv6 30
lv7 32
lv8 34
lv9 36
lv10 38
lv11 40
lv12 41
lv13 42
lv14 43
lv15 44
lv16 45
lv17 46
lv18 47
lv19 48
lv20 50
lv20 entering epic quest 70

Then set trash in level 1 quests to have a +5 to +10 to hit , bosses +10 to +15 ,
build this up through the levels so that generally at "capped ac" trash has between a 50-75% to miss and bosses have between 25-50% to miss.

Why ?

Well with this system it would mean an achievable ac would be possible without making people able to completley out run the AC curve to make them 95% immune to ac .

This would then make having some devotion to ac desirable , without having to put the kitchen sink in to make it feasable