Do you mean as in dodging? If that's the case, you need to be a Journeyman in Acrobatics before you gain the option of dodging. After that, it's simple. To do a quick dodge in combat, hold block and then tap the movement stick/button for the direction you want to dodge in.
I've never pushed a character to that level of Acrobatics, however, so I've never seen it in action, but I've read the booklet from the game.
Yeah, it's really quite simple. Basically if you are a journeyman of acrobatics you can dodge, which is a roll forward, backflip backwards, or striding to either side. All you must do is hold block, move in a direction, and jump. There we go ^^
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My Current Char. LVL : 22 Race : Female Kajit Class : Custom Class Proficient in Bows Listener Guild Master of the Thieves Guild Champion of the Arena Master of the Fighters Guild