There are usually nine different types of armor in Dungeons & Dragons-based games. The higher the AC value of the armor, the better protection it offers against attacks. However, good protection comes at a cost; arcane spellcasters risk spell failure whenever attempting to cast spells while wearing armor.
Piecemeal or complete armors of this grade are meager protection, no better than garments made of cloth or even rags.
Protection equivalent to padded cloth.
Protection equivalent to hardened leather.
Protection equivalent to studded leather or hide.
Protection equivalent to scale mail.
Protection equivalent to a suit of chainmail.
Protection that is equal to banded or splint mail.
Protection on par with half-plate.
Protection equivalent to a suit of full plate armor.
AC Bonus +1
When used properly, a small shield can grant lightweight protection with very little encumbrance to the wielder.
AC Bonus +2
A large shield is effective protection for the adventurer who can afford the added weight and encumbrance.
AC Bonus +3
The tower shield is a veritable wall of protection, though it can be quite cumbersome to carry on an adventure