You can dodge three times until you have to pause with the dodging and catch your breath, also named as being Exhausted. After that you can still dodge, but it's and Exhausted Dodge. An Exhausted Dodge is slower than normal, and if the player is hit he will receive extra damage.
You can see on the dodge buttons how many dodges you can perform at the moment. You can dodge more than 3 times per battle though, your dodges will regenerate. This only refrains players from dodging many times in quick succession.
The amount of times you're allowed to dodge varies with your armor. Equipping lighter armor will allow you to dodge more often without becoming exhausted.
Dual Weapons give players extra Dodge Points, and replace the Block button with a Duck button. Ducking costs two dodge points.