I just noticed as I was looking at the artillerist artificer's Eldritch Cannon class feature. Can the eldritch cannon walk without shooting?

On each of your turns, you can take a bonus action to cause the cannon to activate if you are within 60 feet of it. As part of the same bonus action, you can direct the cannon to walk or climb 15 feet to an unoccupied space, provided it has legs.

It sounds like 'activation' isn't optional, and the move command is an optional part of the same bonus action. Activation say things like "The cannon exhales fire..." or "Make a ranged spell attack..." so it seems that I can't just have the cannon move if there's nothing I want destroyed at the moment. Is that accurate or is there something I'm missing?

Note: Certainly as a DM, I'm going to rule that you can forgo the activation and just have it walk. I just was reading the rules and noticed something apparently weird about them.

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    \$\begingroup\$ Highly related: Can you use your bonus action to move, but not attack with, a spiritual weapon? \$\endgroup\$
    – MivaScott
    Commented Dec 7, 2022 at 22:16
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    \$\begingroup\$ @MivaScott The reason I think it's a bit different here is Spritual Weapon says you "can X and Y", and the discussion is over whether it should be read as decomposing to "can X and can Y" or not. In this case, the text is really clear that you definitely do activate it, and as part of activation it can walk. The activation part isn't behind a 'can' or 'may'. \$\endgroup\$ Commented Dec 8, 2022 at 14:30

2 Answers 2


“I made this walking cannon, but it can only walk while it’s firing” doesn’t make any sense.

I don’t often do this, but sometimes the narrative implications of a ruling are silly enough that I think we can rule it out. “My walking cannon can shoot and walk, but it has to do both at the same time” is a ruling that just doesn’t make good sense narratively. The artificers of the world are not this dumb. This just can’t be what the feature description means. The only thing that makes sense narratively is that the walking cannon can walk without going off.

I get that D&D is not a physics simulator, so bringing expectations about real world physics to the rules doesn’t always work. But it is an arcane tinkerer simulator. It’s a reasonable expectation that every artificer isn’t going to be so dumb as to connect the legs and the firing mechanism to the same machinery so you can’t operate one without the other.

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    \$\begingroup\$ If you really want to find an in-store justification for it, it's possible: "the cannon's legs are driven by reusing energy from the recoil - I wanted to add an independent drive, but the thaumic discombobulator repolarises all connected etheric capacitors every time it fires. No way around it." Not saying this is a good idea, mind you, but frustrating engineering tradeoffs are absolutely on-theme for any '_____ tinkerer' simulation. \$\endgroup\$
    – Toby Y.
    Commented Dec 8, 2022 at 1:38
  • \$\begingroup\$ I agree entirely with your answer -- the rules as written are, in this case, ridiculous and should be ignored. \$\endgroup\$ Commented Dec 8, 2022 at 14:27
  • \$\begingroup\$ @DarthPseudonym In this case, I think we could quibble about what the RAW take really is, because it is unclear, hence your question. But the narrative implications are downright silly. \$\endgroup\$ Commented Dec 8, 2022 at 14:28
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    \$\begingroup\$ @TobyY. Depending on the tinkerers in question, such as the Dragonlance gnomes, it is extremely easy to picture this situation. \$\endgroup\$ Commented Dec 8, 2022 at 17:18
  • \$\begingroup\$ Artificer: "Hi, here's the cannon you asked for: function activateCannon() { fire(); }. Cannon user: "Wow, cool! Does it move? How can I tell it to reposition before firing when the enemy has taken cover?" Artificer: "Erm... Give me a sec. [...] There, done. Just tell it to move, when you activate it: function activateCannon(move) { if (move == true) then { move; } fire(); } → Dunno, seems pretty plausible to me. \$\endgroup\$
    – walen
    Commented Dec 9, 2022 at 7:57

As written, you can only move it when you activate it

The Eldritch Cannon is problematic in several ways -- for example, it has AC, hp and can move, like a creature, but it is not a creature, it is a magical object. The rules for this object state that you can activate it as a bonus action, and only as part of this bonus action you can make it walk or climb. So moving it always involves an activation.

How you narratively dress this up is up to you. Maybe the activation provides the energy to wind up the mechanism for the legs?

If you and your DM do not like this and both think that it is dumb and you should be able to have your li'l cannon buddy walk around without belching fire or making spell attacks, you are free to overrule this.

  • \$\begingroup\$ I was wondering if "activation" definitely implied "firing", rather than just waking up and having the opportunity to attack. But there's a table of cannon type vs. activation result right afterward, with flamethrower being "The cannon exhales fire in an adjacent 15-foot cone that you designate". Flaming vertical upward can avoid damaging allies in some cases (and be a very metal way to walk around), but is not great when you're indoors in a wooden structure. Force Ballista is Make a ranged spell attack, originating from the cannon, at creature or object. You can at least pick a wall. \$\endgroup\$ Commented Dec 8, 2022 at 21:42

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