I’ll be damned if yes.
I sure hope not. 
Well, you can play fine against small monsters at <500ms latency, but don’t expect to play well against bosses.
For me ,saw a few of gameplay on youtube, I guess it a “yes” , atleast with Archer.
Well that depends, if the server lags, then you’re in for a bad time (August 4th). Otherwise you should be mostly fine if you’re under 500ms like @MementoMori said.
F*** me then :I
Planning to get my hands on Archer class.
I really hope 200 ms latency won’t really affect my experience that bad.
Random strip of information.
Credit to @Kiyoshiro
4:45 PM - Kiyoshiro: At least 200 ms here.
4:46 PM - Kiyoshiro: It’s more noticeable when I’m using Wizard or Archer.
4:46 PM - Kiyoshiro: Otherwise, not that much.
4:47 PM - Kiyoshiro: Dodging attacks is significantly harder though…
