Defense Bonus

Defense Bonus-Option
In the standard d20 rules, a character’s skill at attacking gets better as he goes up in level—but not so his skill at avoiding attacks. Characters rely on armor and an ever-growing collection of magic items to protect them in combat. But what about campaigns in which it’s not common or appropriate for characters to go everywhere in full plate?

In Star Trek d20, it is not usually logical to wear any kind of armor, so this is the table used for Starfleet crewmen, due to their experience, they recieve a bonus for armor class when they are not wearing armor.