Starting AC equal to AGI. Always active.
Armor gives AC penalty:
Leather Jacket = 0
Combat Leather Jacket = 5
Leather Armor and LA Mk2 = 10
Metal Armor, MA Mk2 and Tesla Armor = 30
Combat Armor (all types) = 25
For every unused AP you get 1 AC, which lowers the chance to hit of attackers.
Kamikaze
+20 AC
-10% DMG resist
Dodge
+20 AC
HtH Evade
AC increased by 2 for each unused AP, plus 1/10 of unarmed skill