Swift attack allows you to take a full action to attack twice, but a standard attack takes half an action. why do you need swift attack if u can attack twice already?

You cannot repeat an action during the same round, so you cannot make two attack actions in the same round, two move actions in the same round, two re-load actions in the same round, and so on. Some actions can be extended (like Aim can change from a 1/2 to a Full Action if you like), but generally you can only do any given an action once per round.

Therefore Swift Attack allows you to attack twice in a single round, something you cannot normally do.

BYE

More precisely: Any half action can only be performed once per turn.

(And I'm not sure whether it's specified in DH already, but in RT, there's also an action subtype called an Attack Action - you can only perform one of those per turn whatever they are)

I don't think the "no two attack actions" thing is specified anywhere in Dark Heresy. There is just the rule about no two identical half actions (though it ends up with exactly the same result).

borithan said:

Check the errata.

Bilateralrope said:

I was under the impression it was still the no two half actions rule that prevented multiple attacks in a round for DH. Which part of the errata are you referring to? Glancing through, the closest thing I could find was the change to the focus power action.

Core book, page 188. Under the description of Half Action:

"A character can take two different half actions on his turn instead of taking a full action. Note that you may not take the same half action twice."