Armor Class

The Armor Class line gives the creature’s AC for normal combat and includes a parenthetical mention of the modifiers contributing to it (usually size, Dexterity, and natural armor). The creature’s touch and flat-footed ACs follow the combat-ready AC.

A creature’s armor proficiencies (if it has any) depend on its type, but in general a creature is automatically proficient with any kind of armor it is described as wearing (light, medium, or heavy), and with all lighter kinds of armor.