Does Dodge have a cap?

Currently, dodge from abilities is multiplicative and not additive. For example: when you have 25% dodge on your monk from just dexterity, and enable the Mantra of Evasion, it will not actually add a flat 15% to your dodge, it will only add 11.3% dodge (rounded up). This is because it multiplies by the remaining number, which in this case is 75. With Mantra of Evasion still enabled you can try dual welding with the Guardian's Path passive. It will then multiply your current remaining number: 63.7 by 15%, now giving you 9.6%(9.555~) instead of 15% for a total dodge of 45.9%(45.855~).

Additionally, based on these calculations: You will be able to max out your dodge by stacking 8000 dexterity. I doubt this is achievable in game, but you may be able to get close with an unrealistic amount of dexterity...

So, it appears that there is a cap because it will be very hard to reach 100% with such mechanics.