If you have three ranks in the Mobility skill, this Dodge bonus to Armor Class increases to +3. Note that three ranks does not mean a +3 Mobility skill bonus, it means you must have spent three skill points on Mobility.
You can activate the Fight Defensively ability in the Abilities tab (the middle tab) above the action bar, and it can be toggled on and off at will.
At the mansion of the Swordlord Jamandi Aldori, adventurers have gathered, lured by the promise of dominion should one of them conquer the nearby Stolen Lands and oust its current overlord - the Stag Lord. You are one such adventurer, and Jamandi’s offer isn’t just a benevolent call-to-arms to make the Stolen Lands safe for normal folk, there’s political angles to its conquest, and the ultimate allegience of its new ruler. More than that, however, a sinister, primordial force has her own interests in the Stolen Lands, and a desire to see new rulers rise… and fall. The Pathfinder: Kingmaker guide includes a full walkthrough of the game’s main campaign, including various side quests, companion quests and strategies.