Can a battlesmith artificer command his Steel Defender to attack a creature that the artificer can’t see


The Artificer can see and hear his steel defender but not the enemy.
The Steel Defender can see and hear the Artificer and can see and hear the enemy.

Can the Artificer use its bonus action to make the Steel Defender attack the enemy?

Best Answer

Yes, they can

The Steel Defender feature says

In combat, the 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 another action. That action can be one in its stat block or some other action.

There is nothing in there limiting the actions to involve only opponents you can see. It can be any action.

Obviously, to command it to attack a specific creature, you need to be aware that the creature is present. But a creature you cannot see is not automatically hidden from you.

Note however, that the Steel Defender's Force Empowered Rend attack has a limitation:

Force-Empowered Rend. Melee Weapon Attack: your spell attack modifier to hit, reach 5 ft., one target you can see. Hit: ld8 + PB force damage.

"You" in the defender's stat block refers to the caster (for example, it has hit points of "2 + your Intelligence modifier + 5 times your Artificer's level" and the defender does not have any artificer level). The defender itself is referred to as "the defender" in the stat block, as in the Defense Attack reaction ("The defender imposes disadvantage […]").

That means, while you can command it to attack the creature, it cannot carry out the Force Empowered Rend to do that, as that works only on a creature you can see.