[RPG] When does a Chain Familiar’s attack occur using the new UA Eldritch Invocation: Chain Master’s Fury

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When using the new UA Eldritch Invocation, Chain Master's Fury (from the UA Class Feature Variants, p. 10):

Chain Master's Fury

Prerequisite: 9th level, Pact of the Chain feature

As a bonus action, you can command your familiar
to make one attack.

When does a Chain Familiar’s attack occur?

  1. The familiar attacks immediately using the Warlock’s bonus action.
  2. The familiar attacks immediately, using the familiar’s reaction.
  3. The familiar attacks, on the familiar's turn, using the familiar’s reaction.

Best Answer

Immediately during your bonus action.

The Pact of the Chain Pact Boon (PHB, page 107) states,

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 means that the familiar will immediately use its reaction and make an attack, replacing one of the attacks during the Warlock's attack action. However, the Chain Master's Fury invocation makes no such statement that it requires any action on the familiar's part. In other words, it is a free action for the familiar.

Immediately, as part of your bonus action, the familiar makes an additional attack. This leaves your warlock open to use his action for something else like Eldritch Blast, or to make two attacks if you have the Thirsting Blade Pact of the Blade Warlock Invocation or Extra Attack feature from another class.