The group that I am playing in just switched back over to Deathwatch from Rogue Trader. I was allowed to continue to us my Tech Marine and just earned enough XP to take the "Master of Blades" trait. I have a Power Axe (Master Crafted) already sig'ed to me as well as having a Servo Harness that makes my Servo Arms (Master Crafted). I am thinking of doing the MoB's combo of "Power Axe" & "Chainfist." Now the first Question is, sense the Axe itself is master crafted would I calculate the Chainfist damage as Master crafted too?

Second; I've done the math and it is scary how much damage a Tech Marine can do with such a weapon combo.

( WS )43 ( BS )60 ( S )46 ( T )50 ( Ag )62 ( Int )68 ( Per )39 ( WP )43 ( Fel )40
[AXE]( Strength )46 (46+46=92+20=112) & ( ServoArm )85 (85+85=170)

[CHAINFIST]( Strength )46 (46+46=92+46=138+20=158) & ( ServoArm )85 (85+85=170+85=255)

Power Axe Melee 1D10+10E Pen7 {Damage in hand 22min to 31Max}(Damage in Servo Arm 28min to 37max)

Chainfist Melee 2D10E Pen 9 {Damage in hand 17min to 35max}(Damage in Servo Arm 27min to 45max)

MCChainfist Melee 2D10+2E Pen 9 {Damage in hand 19min to 37max}(Damage in Servo Arm 29min to 47max)

Now did I do my math correctly or did I miss something to change the results?

Unnatural Strength doubles the strength bonus (the 10s digit) not the characteristic. so the 46 Strength gives you a base SB of 8 (10 with power armour) and the servo arm has a SB of 16 instead of 17. This matters most when making tests based on these characteristics but also has an effect on how much damage you do.

You are using your Servo-Arms as hands to swing a weapon? That's weird, and game-y, and awkward. Servo-Arms are tools, not extra hands.

Now that I look at this more, you've done almost everything wrong.

A Servo-Harness allows you to incorporate weapons as additional arms. It isn't clear whether those arms use the Strength bonus from a Servo-Arm or if they use the Strength bonus of the Character. I seriously doubt that increasing your melee damage is an intended function of the Servo-Harness though.

In addition to this, you've misread how calculating damage for Unnatural Strength works.When you make a melee attack you add your Strength bonus to your damage. Unnatural Strength doubles your Strength bonus. A Chain Fist increases that bonus by one step, tripling your Strength bonus when you calculate damage. It should look like this.

Power Axe

Damage from SB=10 [this assumes your strength is in the 40s like your example.]

SBx2=8 plus 2 from your power armor.

Chain Fist

Damage from SB=14

SBx3=12 plus 2 from your power armor.

You do not literally double your strength, that would be beyond broken.

If your Power Axe is master-crafted you would calculate the Chain Fist damage as master crafted as well.

A couple of things to note:

- The chainfist is a 'mounted' weapon. usualy unly used on terminators and not usable by a standard marine. I wouldn't think you could use one unless it was mounted on a servo arm with the Machinator Array talent. and then, only maybe. This is the only way I'd let someone use the strength of a servo arm with a melee weapon. (it's not like you usualy need something more than the arm itself.)

- The GM is the one who picks the weapons from the mark of distinction, so If they're cool with it then have fun.

the power fist is plenty good, or the ever-broken Thunder hammer flat of the blade concept is less problematic then a chainfist.

Nathiel said:

The Master of Blades Trait allows the player to swap weapon profiles on a single weapon, so the fact that the Chainfirst is a 'mounted' weapon matters not in this example. And thank you everybody for the information about the Unnatural Strength information, it will change my numbers a little, but I can deal with that.

I imagine not using weapons with your servo arms will change them a lot...

Using the profile of the weapon includes the method of weilding it. If you used your power sword with the profile of a power claymore it would have to be used two handed. I suspect that that would not be a problem when mounted on the servo arm, but I still think most reasonable GMs will pick some thing other than chainfist.

You're working too hard Techmarine. Put a Breaching Auger on a servo arm with the Machinator Array talent and call it a day. It will do the same damage as your chainfist nonsense without making your GM and fellow players groan. At only 18 req, you can't beat that bargain! Oh, and it opens doors. Thick ones.