So, the Errata deals with how swift attack, lightning attack, two-weapon wielder, ambidextrous and gunslinger combi up. But there's no mention of furious assault. Can you use furious assault with other multiple attack talents? Indeed, can you use any special type of attack with multiple attack talents?

In favour of "no", furious assault only works with an all-out attack, which is a full action so logically can't be combined with another full action such as a swift attack. Also, you could end up with a pretty sick combo: all the above talents plus furious assault would make for a potential of 5 hits in a round, all of which would get the benefits of an all-out attack.

In favour of "yes", two weapon wielder and swift attack both say you must use a full action to get the benefits, yet they can be combined. Also, any other answer makes furious assault essentially worthless for anyone who has lightning attack, and arguably so for swift attack as well. In fact, it would make going on an all-out attack worthless for anyone with those talents, which seems to take away from the flexibility and fun of the game.

So... thoughts?

The only actions you can take that can improve your chance to hit in melee are aim, charge and all-out attack, and the all-out attack is the fastest way to get +20 to hit, which is a big boost. And with the Furious Assault talent you get to spend your Reaction to make a second attack, the real bonus of it is that you retain all bonuses of the original attack. I don't think that it needs to be combined with any other talent because they are best used different situations; Furrious Assault should be used when your chance to hit is not that great, and Swift Attack/Lightning attack should be used when your chance to hit is great. That's the way I see it anyway.

I would say yes, but as stated Furious Assault costs your reaction, so leaving you defenceless

xenobiotica said:

Surely the only factor determining your chance to hit, with rare exception, is your WS? So Furious Assault is only for low-WS characters?

(Thinking about the numbers involved, roughly, swift attack will be worth more than an all-out attack if your WS is at least 20, while lightning attack will be worth more than an all-out attack if your WS is at least 14. Furious assault makes an all-out attack a bit better, but since you have to hit with your first attack to get the benefit, it isn't going to push those numbers up too much higher. So it looks like you'd have to have a pretty poor WS to make it worthwhile to go for an all-out attack once you have swift attack or better. Since you have to have at least WS 35 to get it in the first place, it isn't looking like a good bet!)

Santiago said:

This is an excellent point, though with five attacks, the best defence may well be a good offence!

Cardinalsin said:

Fatigue can often be a factor, as can darkness, difficult terain, called shots or the lack of a quality weapon, but I have to admit I haven't crunched the numbers as you have. And another advantage of Furious Assualt I forgot to mention is its use together with the Frenzy talent, since you're forced to take the all-out attack action if you can . Sure the Battle Rage talent gives you the oppertunity parry while under frenzy, but only Savant Psykers can take that talent before Rank 7 (Rank 5 for a Savant Psykers, Rank 7 for Zealot Clerics and Rank 8 for Imperator-Mortis Assassin and Storm Trooper Guardsmen), but even then you're still not allowed to dodge.

EDIT: and I don't think that my example circumstances above (mostly darkness and difficult terrain of course) are really rare, they make for nicely varied battles and should be used every so often.

xenobiotica said:

This is an excellent point! Does this mean that if you're in a frenzy you can't make a swift or lightning attack? I think on balance this swings it for me - frenzy would be really poor if it couldn't combo up with lightning attack.

Cardinalsin said:

That is indeed what it means. Swift attack and lightning attack cannot be used while in frenzy. But frenzy has its own advantages: +10 to WS, S, T and WP and you gain immunity to fear, stunning effects, and the effects of fatigue. Before the errata it was rubbish, but now it's much better.

I didn't realize how much the errata changed Frenzy, I might actually take that at some point since I never parry or dodge anyway