I can't find a thread explaining this for new players, so i put it here.
When you target a mob, a boss, or another player, you may see 3 white shields around it/him.
You can have 3 shields on the same side, or 1 shield on each side (top/left/right), or any combination.
Those shields affect the amount of damage you deal on your target like follows :
0 shield on 1 side = +33% damage on that side
1 shield on 1 side = + 0% damage on that side
2 shield on 1 side = -33% damage on that side
3 shield on 1 side = -66% damage on that side
You as a player also have those shields, they're yellow on your screen. By default, you have one shield on each side, so you take "normal" damage from any side, and only increased damage if you get hit in your back.
You can manage those shields with ctrl + 2/3/4 (might vary depending on your settings, check your control panel).
For instance you might need to have the 3 shields up on your front side, because you predict that a certain mob will only hit that side.
The shields on your target also change when it gets hit.
For exemple, hit repeatably one mob on the right side, and quickly, you'll see his shields moving to that side, until it gets the 3 the shields up there.
Shields also change when you move around your target. Even if your target got 1 shield on each side, if you rotate around it, you'll see there will be one spot where all the shields are down, but you will also see several spots where only one side is exposed, sometimes 2.
The point is to find those exposed sides to maximize your damage output. This is the melee game.
