Can a Pact of the Chain Warlock forgo an attack to let their familiar use a Coiling Grasp Tattoo?

Question

If a Level 3 Warlock picks Pact of the Chain, they get an altered version of the find familiar spell.

You learn the find familiar spell and can cast it as a ritual. The spell doesn't count against your number of spells known. When you cast the spell, you can choose one of the normal forms for your familiar or one of the following special forms: imp, pseudodragon, quasit, or sprite.

Additionally, when you take the Attack action, you can forgo one of your own attacks to allow your familiar to use its reaction to make one attack of its own.

This question will revolve around the "when you take the attack action, you can forgo one of your own attacks to allow your familiar to use it's reaction to make one attack of its own" part.

Now, as far as I know, familiars are allowed to have/use magic items, so if I give an Imp the Coiling Grasp Tattoo, would I be able to forgo one of my attacks to allow the Imp to make the attack with the Tattoo?

Grasping Tendrils. While the tattoo is on your skin, you can, as an action, cause the tattoo to extrude into inky tendrils, which reach for a creature you can see within 15 feet of you. The creature must succeed on a DC 14 Strength saving throw or take 3d6 force damage and be grappled by you. As an action, the creature can escape the grapple by succeeding on a DC 14 Strength (Athletics) or Dexterity (Acrobatics) check. The grapple also ends if you halt it (no action required), if the creature is ever more than 15 feet away from you, or if you use this tattoo on a different creature.

Where this gets funky, is that the Grasping Tendrils require an action of the user, which in this case would be the Imp. But the altered find familiar says that the attack the Imp does is used as a Reaction. So would this work?

And if it doesn't, I pose another question. In the baseline find familiar spell, it is stated that the familiar cannot attack:

Your familiar acts independently of you, but it always obeys your commands. In Combat, it rolls its own Initiative and acts on its own turn. A familiar can't Attack, but it can take other Actions as normal.

I almost dropped this post, as I just assumed that the idea of using the Coiling Grasp Tattoo wouldn't work. But after some research, it appears that it is widely agreed upon, that the Imp can use something like the Wand of Magic Missiles

This wand has 7 Charges. While holding it, you can use an action to expend 1 or more of its Charges to cast the Magic Missile spell from it. For 1 charge, you cast the 1st-level version of the spell. You can increase the spell slot level by one for each additional charge you expend.

The wand regains 1d6 + 1 expended Charges daily at dawn. If you expend the wand's last charge, roll a d20. On a 1, the wand crumbles into ashes and is destroyed.

Which also needs an action to cast. Can I then assume that the Coiling Grasp Tattoo will work in the same manner? And if not, what allows the Wand to bypass the find familiar's "can't attack" rules while the Coiling Grasp Tattoo cannot?

Answer 1

Coiling Grasp Tattoo requires the wearer to use an action.

As you have noted, Grasping Tendrils states:

While the tattoo is on your skin, you can, as an action, cause the tattoo to extrude into inky tendrils, which reach for a creature you can see within 15 feet of you.

This means that it requires the use of an action, in particular, the special action granted by the tattoo to its wearer. This means that the familiar cannot make the Grasping Tendrils action with its reaction (except through use of the Ready action).

The familiar can use Grasping Tendrils on its turn.

You have also noted the find familiar description, which states:

A familiar can't attack, but it can take other actions as normal.

However, the Grasping Tendrils action is not an attack at all:

The creature must succeed on a DC 14 Strength saving throw or take 3d6 force damage and be grappled by you.

So the usual restriction on familiars doesn't even apply, as the tendrils force a saving throw, rather than make an attack, and the tattoo grants the wearer the ability to use the Grasping Tendrils action. Here, Grasping Tendrils falls under "other actions as normal", since it is not an attack.

Answer 2

No on both

Additionally, when you take the Attack action, you can forgo one of your own attacks to allow your familiar to use its reaction to make one attack of its own.

Grasping Tendrils. While the tattoo is on your skin, you can, as an action**

This wand has 7 Charges. While holding it, you can use an action to expend 1 or more of its Charges

The ability does not grant your familiar an action. It lets your familiar make a single attack. The familiar cannot use either of those items, as they require an action. The familiar can make a vanilla attack, or if they have the option, a special attack that takes the place of a single, regular attack (i.e. if familiar gained the trip attack maneuver via the martial adept feat, it could make a trip attack here, if it had superiority dice remaining).

As a counter example, a fighter with Extra Attack could not use their two (or more) attacks to fire the wand of magic missiles multiple times with a single action, even though they can attack multiple times with an action.