If a heavy bolter fires off a full auto burst, do I roll ONE time and count how many shots hit by the degrees of success based off the one roll to hit? Or do I roll the hit for every single shot in the full auto burst and any degrees of success just automatically apply to the next rolls I would need to make?

One roll for all shots, and likevise one dodge-roll for all the shots that hits, counting DoS in the same way.

So one dodge can dodge 10 shots from a full auto burst or one dodge for one shot from that 10 shot burst?

One dodge for the whole attack . When attacking, basic success gives you one hit . Each additional DoS gives you an additional hit . Similar with dodging. Basic success negates one hit of the attack . Further DoS negate more hits . Resolve damage on a per hit basis. Each hit does full damage.

Alex

So when dodging additional DoSs provide more hits dodged?

They are correct.

One attack roll with Semi/Full.

A successful attack will generate 1 hit, plus:

Semi: One additional hit per 2 DOS

Full: One additional hit per 1 DOS

Dodge is similar, A successful dodge roll will negate 1 ranged hit, plus:
One additional hit negated per DOS.

Oh ok, I gotcha. That makes sense. Thanks!

Ok, I'm a little confused now, I think I've been playing Semi/Full completely wrong.

So for example if a Heavy Bolter fires Full, the ten shots are determined by one to hit roll. Then for every degree of success after the first you get an additional hit?

If the target dodges once successfully, he dodges all of the shots?

Also one last question, if the Full Auto burst were to hit a Horde, it'd do one hit if successful and then one more for every degree after that, but since the ammo type counts as explosive it technically hits 2 guys for every one hit?

Is this correct or have I been doing this all wrong?

0. Use the errata weapon stats from the Support section of this site. Seriously.

1. When you shoot, one shot hits ("score a hit") for basic success (0 Degrees of Success). For each additional DoS, another shot hits - up to weapons's ROF.

2. When you dodge the, the same goes in reverse: -1 hit for basic success, -1 hit for each DoS in addition. You reduce the number of hits calculated in the previous step.

3. The errata explains that the explosive extra horde damage is per attack, not per hit. So only +1 in total.

Alex

Space Marine bob shoots chaos marine steve with a heavy bolter.

Bob makes his full auto attack and needs a 42 to hit, he rolls a 21.

Because Bob's attack hits he scores one (1) hit, but Bob succeeded in his attack roll by two (2) degrees of success (42-21/10, round down) so Bob also gains an additional two (2) hits, one for each DOS.

Steve is hit by three (3) heavy bolter rounds.

Steve is no dummy and knows those shots can hurt him, so he decides he will try to dodge them. His dodge skill is 39 and he rolls a 27. Since he succeeded in his dodge test he successfully dodges one (1) hit, but because he succeeded by one (1) degree of success (39-27/10, round down) he manages to dodge a second hit from the same attack.

So Steve manages to dodge two (2) of Bob's three (3) hits, but still gets hit by third and bob now gets to roll damage against steve.