Not the best title, but I can’t think of anything better.
This issue occurs on both Engineer and Guardian, they are the only ones I have tested. It is much easier to reproduce this on Engineer.
Engineer: Shield Block (5): If you press 5 to throw the shield just before an enemy attacks you, you will both stun the enemy and throw the shield. This happens when you block during the Throw Shield animation (but does require a bit of timing).
Guardian: Getting attacked exactly when Protector’s Strike ends (mace 3 skill), you will both block the attack and get protection. The block will not explode or deal any damage. I have tested this without aegis. (cleared aegis, then used Virtue of Courage and got rid of that Aegis as well). This is tedious to test on Guardian, as you must time it just right. I have been testing it on Dolyaks in the field and a friend has been doing it on golems in the mists.
It’s nothing game breaking on Guardian, but I always exploit this on Engineer to get 3 stacks of Defiant off Champion mobs with a single skill. So it’s very reliable.
Many thanks to Raylemia of Desolation for helping test bugs on Guardian
(edited by Y u mad its vydia.6324)