Curious About Tentacles

If a mutant has the tentacle mutation, does "grappling" replace one of his attacks? Here's the rule for reference:

Tentacle; Cost: 35 gc
One of the mutant’s arms ends in a tentacle. He may grapple his opponent in close combat to reduce his attacks by -1, down to a minimum of 1. The mutant may decide which attack his opponent loses.

I´d say yes, it is grown on one of his arms (unless he's got extra arm), so usualy on his off hand. So it replaces his off hand attack. Different situation occures, when you buy it to a possessed model, since he doesn´t use his off hand for attacking.. that is the way I understand it.

I would say a mutant having a tentacle would limit it to a single hand weapon, unless he also had an extra arm.

This was discussed a while ago: https://boringmordheimforum.forumieren.com/rules-and-gameplay-f1/tentacle-mutation-possessed-equipment-t3108.htm

No consensus was reached in that older thread, but a few house rules and interpretations were shared.

Clearly the mutations description is misleading folks. GW often has trouble separating flavor text from rules. While the flavor text describes the arm ending in a tentacle, the rules do not say it prevents a mutant from using a weapon as well as grappling an opponent. Compare this with a claw which clearly does not allow any weapons to be used with the same limb.

Also compare the costs and abilities of extra arm and tentacle, which makes more sense?

• Extra arm - 40 gold for an extra attack
  
• Tentacle - 40 gold for a loss of an attack and the ability of reducing one opponent's attacks by one, provided they have more than one.
  

In this case I would take the first one 100% of the time

• Extra arm - 40 gold for an extra attack
  
• Tentacle - 40 gold the ability of reducing one opponent's attacks by one, provided they have more than one.
  

In this case I would take the arm for an offensive character and the tentacle for a defensive character. Both have their roles and it depends on your play style and model preference, rather than one being clearly better.

We have always played that the tentacle is a separate growth, simply because it wouldn't be worthwhile otherwise. It also doesn't state that the tentacle arm may not use weapons, the way a great claw does.

I agree that it is obvious those mutations description are broken (or let´s say not well-considered) and the FAQ about claw (which is pretty much the same as for tentacle I´d say) says, that you need an arm for it. So this next awesome explanation makes different conditions for possessed and mutant using it, since mutant loses one attack (another thing designers mistook, I guess). We keep playnig it like this, but we dropped the cost of these mutations for mutants by 10 gc

There are so many rules in RB, which are not clearly stated, that you can use the argument "it is not stated, so I is this way" on half of them. That´s why we composed our group revision, where we tried to make all unclear parts clear, with no more discussions about it.

Oh man I could totally wield an ax in a tentacle. I don't know why anyone would think otherwise.

I think on a possessed it's pretty clear that it wouldn't reduce their attacks because they're not actually dual wielding; ergo just get it on your possessed and avoid this confusion altogether!

I could see ruling that it takes an arm, thus losing a potential attack, if you reduce the cost. That makes sense fluff-wise and would still be balanced.