First about the Frost blade it says that it adds +1 to the user's strength. That means you must use the frost blade for the extra strength.
The Scorpion Chainsword says that it adds +1 strength to the models attacks. If he makes attacks, they are at +1 strength, and don't even try to go on about their guns being at +1 strength because it says attacks, not shots.
Except they use 'Shots' and 'Shooting Attacks' interchangeably, but let's not go there.
If a guy has a Scorpion Chainsword his A abilities have +1 strength than normal.
And a model with a powerfist has his Strength score doubled. Except it only does that when you use it.
Just like the Scorpion Chainsword.
As for pg. 46 paragraph 2. It says only 1 type of special attack can be made. So no you can't combine a force weapon and a powerfist as they are both special attacks, but the Scorpion Chainsword doesn't say that the +1 strength bonus is only for attacks made with the weapon.
And the powerfist doesn't say that the double strength is just for attacks made with it.
And the force weapon says nothing about actually having to use it. Just that if you score a wound you can make a psychic test and use its ability.
It just says for the models attacks. If it said "+1 strength to the users attacks", I would agree that you don't get the bonus. If it said "+1 strength to attacks made with it," I would agree that you don't get the bonus, but it just says +1 strength to models attacks. This means that the +1 strength bonus isn't for its own special attack, just the model who is equipped with it's attacks.
Does the *weapon* grant you a bonus in the assault phase? Does it make your attacks special, in some way? Then guess what, it's a special attack. If you want to use your special +1 strength attacks you cannot combine it with the effect of another weapon.
As for the powerfist not saying that you only double strength for it. It does specify that. It reads that it doubles the user's strength, ignoring armour saves. Which means you either get both effects (doubling of strength and ignoring armour saves) or you don't get any because again it says that it doubles the users strength, implying that you must use it for the benefit.
Alright, so it gives you double strength and allows you to ignore saves...it still never says that you actually have to hit someone with it for that to be in effect. The only thing directly tied to attacking with it is the initiative penalty.
If you want to be absurd, I can be absurd too.
Even if you are right in saying that the weapon magically bestows a bonus without being used, attacking with +1 to your strength as a result of a weapon is a Special Attack, wouldn't you say? It's an attack that does not act as normal because it was altered, in some way, by a weapon.
If you want to use your special +1 str attacks then you can't stack them with any other special attack.
You want to get into black and white rules, there it is.
Note that the rules don't specifically say 'special weapons' they say 'special close combat attacks' (Also note that here they specify 'close combat' attacks, as opposed to other kinds of attacks?)
So the model with the chainsword and the claw has more than one special close combat attack.
He has a +1 str attack that works at his full initiative, and he has a 2x str attack that ignores armor and works at I1.
He has to pick one.
The weapon doesn't say it adds a bonus to the model's strength score (like Furious Charge would), it says it adds it to his attacks, thus making a form of special attacks.
I think that's the answer right there. These attacks that have been altered by the sword are special attacks, period. No matter whether the attack is made with the sword or a magically augmented headbutt, it's an attack that was made special, it doesn't stack with other special attacks
Ya, that strength 7 instead of 6 makes the Exarch such a hardass.....
It doesn;t matter how big or small an advantage is. If it;s against the rules it's something you should point out.