Does the Battle Smith artificer's Steel Defender get a full turn?

Question

I know the Steel Defender uses your initiative and goes immediately after you. What I'm not sure about is what is can actually do on its turn.

Does a Steel Defender get a full turn?

1. Action
2. Free object interaction
3. Bonus action
4. Movement

I know it has the statblock that tells you what actions it can take, but it does not say anything about having or not having a bonus action and what it can do with that. It also does not specify interactions.

Example 1

The Steel Defender uses a bonus action to activate boots of speed and now has the ability to move 80 feet around the battlefield, potentially causing enemies to use up their reactions to make opportunity attacks and positioning itself at a choke point. It then takes the Dodge Action.

Now we have a Speedy Gonzales that can get up next to people and provide cover, Help, or be a damage sponge before zipping over the the other side to block a charging enemy that appeared from around that corner you never checked.

Example 2

With a party member about to die, the Steel Defender pulls a potion of healing out of a bag (item interaction) and Dashes (action) to a party member. The party member, on their turn, takes the potion and drinks it.

It basically functions as a mobile vending machine that can run in hand out potions and use its reaction to impose disadvantage.

Are both, either, or neither of these examples possible within the rules? What is the action economy available to the Steel Defender?

Answer 1

It does!

The Battle Smith artificer's Steel Defender feature says (E:RftLW, p. 61):

In combat, the defender shares your initiative count, but it takes its turn immediately after yours. It can move and use its reaction on its own, but the only action it takes on its turn is the Dodge action, unless you take a bonus action on your turn to command it to take another action. That action can be one in its stat block or some other action. If you are incapacitated, the defender can take any action of its choice, not just Dodge.

What this tells us is that the Defender will take a specific action unless directed by you. It doesn't prevent the Defender from taking bonus actions (BA) or item interactions. It takes an entire turn, whose Action is restricted by the Artificer. The reason it specifies that the Defender can move and use its reaction on its own is because those appear on its stat block, unlike any sort of BA.

That being said, a DM could rule that, just like Actions, the Artificer would need to do something in order for the Defender to use its Bonus Action in a given way (default being not using the BA). After all, it is a creature with -3 INT, would it remember to stop attacking in order to go grab a random flask from a backpack and carry it somewhere else? The rules don't always account for edge cases like this, and each DM should adjudicate what works best for their table.

Answer 2

The Steel Defender only does what the rules specifically say it does.

For reference, the Battle Smith artificer's Steel Defender subclass feature says (E:RftLW, p. 61):

In combat, the steel defender [...] can move and use its reaction on its own, but the only action it takes on its turn is the Dodge action, unless you take a bonus action on your turn to command it to take one of the actions in its stat block, or the Dash, Disengage, Help, Hide, or Search action.

There is nothing in the rules that would prevent NPCs from having their full supply of activities per turn in combat, including a bonus action and a free item interaction. So technically, yes, a steel defender has those. But the rules above are pretty clear about what you can do with a steel defender, which includes moving, taking reactions, and a list of specific actions, but does not include any bonus actions or item interactions.

In other words, while your steel defender technically has a bonus action and item interaction available to it, it never uses them on its own and you have no way of instructing it to do so, which is functionally the same as if it didn't have them at all. Note that "interact with an object" is not one of the listed actions, so by RAW, you can't instruct your steel defender to use its action to interact with a second object, which suggests that you can't tell it to interact with a first one, either.

...but ask your DM

Your DM should feel free to rule otherwise on a case-by-case basis. While it's entirely reasonable that a Steel Defender may not be able to understand a complex instruction like "dig through my bag and bring me the potion of water breathing" or "twist the dial ten degrees to the right", and may not be physically capable of turning a doorknob or speaking the command word to activate a magic item as a bonus action, it seems absurd that a steel defender could not perform simple object interactions such as knocking over a table or pushing a rock.