Robotstyle

Get them to read the books, that'll give them most of the story

Vulnerability reduces armour by a number i can't remember the number that is used but am going to use -40 toughness.

Taking 300 as a base damage figure and 4(-40 toughness) as a reduction to an armour of 100.
1 stack, 100 armor reduced by 4 to 96 armour, causing and extra 4 damage to leak through = 304 damage
5 stacks, 100 armor reduced by 20 = 80 armour, causing 20 damage to leak through = 320 damage.

So the amount of damage you are doing at base makes no difference via the reduction of armour to how much extra damage you do.

This is how you would expect it to work for all armours. Instead with light and mediums armours appear to take a % of the damage extra.

1 Stack:
Heavy = 0% less damage. - 4 armour = 4 extra damage (4)
Medium = 40% extra damage. -4 armour (-1.6 extra) = 5.6 extra damage (5)
Light = 60% extra damage. - 4 armour (-2.4 extra) = 6.4 extra damage (6)

5 Stacks:
Heavy = 0% less damage. - 20 armour = 20 extra damage (20)
Medium = 40% extra damage. -20 armour (-8 extra)  = 28 extra damage (28)
Light = 60% extra damage. - 20 armour (-12 extra) = 32 extra damage (32)

Hopefully this makes it seem a little less random, as you can see by the OP's figures in (brackets) it appears to round down to whole figures.

[quote name='Leyana' timestamp='1335860950' post='1396002']
A little something to add:

The 'numbers go red indicates out of range' thing is a little iffy. I've found that if you are standing on higher ground than the target, you can hit targets when your skill numbers are still red. I've only tested this with a bow mind, so things which don't have a parabolic arc might be different.

Otherwise, good post.
[/quote]

To add the number 3 skill on my engineers pistol would often hit whilst it was red and "out of range" whilst on a level ground.

Emida said:

4 Hours 30 mins here @ 250Kb/sec

Quote

4 max class specifics
5 weapon skills
5 utility skills
/Fail key binding

My binding (I play on a laptop so the F Keys are pretty near the number keys).
F1,F2,F3,F4 - Class specific
1,2,3,4,5 - Utility skills
q,w,e,r,t - Weapon skills
S,X,Z,C - Movement
A,D - Strafe
\ - dodge
v - Auto run.