
Derrack |
Safe to assume you are new to the system? In Pathfinder (and at least 3.5 D&D and beyond) the higher the AC the harder you are to hit.
Example, say your AC is 30. The enemy rolls a d20 and gets a 10. Their Base Attack Bonus is 5 and weapon bonus is +3, that combines to an 18. 18 is less than your AC of 30 which means the attack misses you.
Example the two, again your AC is 30. Enemy rolls and gets a 19. Base Attack Bonus is 8 and weapon bonus is +4. Total equals 31. That total is higher than your AC of 30 so you get hit.
I hope that helps.