Say I cast the Speak with Plants spell, targeting a plant creature, and during the duration, I cast the Geas spell on the plant. Can I continue to control the plant after the Speak with Plants spell ends?

  • \$\begingroup\$ Do you have a reason for thinking it will or won't work? \$\endgroup\$ – Someone_Evil Jan 27 '20 at 23:57
  • \$\begingroup\$ @Someone_Evil since geas can only be cast on a creature that understands me, I don't know if geas would continue to work after Speak with plants is gone \$\endgroup\$ – Deus Jan 28 '20 at 0:00
  • \$\begingroup\$ Related: Are plants creatures or objects? \$\endgroup\$ – Someone_Evil Jan 28 '20 at 0:00
  • \$\begingroup\$ @someone For what it's worth the speak with plants spell does explicitly mention something called a "plant creature" though I'm unsure what that means \$\endgroup\$ – Medix2 Jan 28 '20 at 0:01
  • 1
    \$\begingroup\$ Related: Is a spell suppressed or removed when the target temporarily becomes invalid? \$\endgroup\$ – AgentPaper Jan 28 '20 at 6:18

"You place a magical command on a creature that you can see within range". Plants, like humanoids, monsters, and undead, are creatures, so they are valid targets for the spell. You can only give the initial command while the plant can understand you, but after that, it will follow those commands or take psychic damage, and will be "charmed by you for the duration". You will be unable to issue additional commands without casting Speak with Plants again, as "a creature that can’t understand you is unaffected by the spell".

  • \$\begingroup\$ I think it would help to provide the reasoning for why the target of a spell only needs to be a valid target when the spell is cast, not for the entire duration. (There's probably a question on here that covers it, but I can't think of one) \$\endgroup\$ – recognizer Jan 28 '20 at 3:58
  • \$\begingroup\$ Why do you think you can give it additional commands at all? \$\endgroup\$ – NautArch Jan 29 '20 at 15:42

Geas will continue to have an effect.

Here's the first few sentences of geas, with my emphasis:

You place a magical command on a creature that you can see within range, forcing it to carry out some service or refrain from some action or course of activity as you decide. If the creature can understand you, it must succeed on a Wisdom saving throw or become charmed by you for the duration. While the creature is charmed by you ...

The first sentence defines what the spell can target: a creature that you can see within range. Any creature, including a plant that qualifies as a "creature", is a valid target, provided that you can see it and it's within the 60-foot range.

The creature does not need to understand you to be a valid target. You can geas a moose if you want, and the spell will take effect.

The second sentence defines what happens, and the first part of that sentence sets a condition for what happens: if the creature can understand you. This is because you may not know if a creature can understand you when you cast the spell! If you geas an orc and issue commands to it in Old Toonish, you're risking the spell having no effect because the orc grew up in the southlands and can't make head nor tails of your Toony accent.

If the creature can understand you, and it fails a saving throw, then the creature is charmed, and the condition for the remainder of the spell's effects is defined: while the creature is charmed by you. Note that this also doesn't say anything about the creature understanding you; they just have to remain charmed (that is, having the charmed condition) by you.

So: If you cast speak with plants:

You imbue plants within 30 feet of you with limited sentience and animation, giving them the ability to communicate with you and follow your simple commands.

If you then geas one of the plants (assuming your DM agrees it's a creature), then the plant can almost certainly understand your commands and it may be affected by the spell if it fails a Wisdom save.

However, when speak with plants wears off (after its duration of ten minutes), the plants will lose their sentience and animation; depending on the nature of your command, they may be incapable of obeying your instructions, and thus may take psychic damage, etc. The geas is still in effect; it's just that the plant isn't any good at following the command you gave it.

  • \$\begingroup\$ Interestingly, would that mean it would take the damage? \$\endgroup\$ – NautArch Jan 29 '20 at 15:57
  • 1
    \$\begingroup\$ @NautArch My reading of geas is that incapacity to follow the command doesn't prevent the damage from being dealt. You could command someone to juggle six hundred-pound anvils for an hour every day. The only restriction is that you can't command the target to do something suicidal; you can command them to do something that seems impossible. \$\endgroup\$ – Marq Jan 29 '20 at 16:30

Geas is probably suppressed, but ask your DM

According to Jeremy Crawford:

There's no rule governing what happens when a valid spell target temporarily becomes an invalid target. A good rule of thumb is that the spell is suppressed while the target is invalid.

This suggests that, since the Geas spell requires the target to understand you, then the spell is completely suppressed after Speak With Plants ends. However the spell is only suppressed, not removed, so if you cast Speak With Plants again or otherwise reestablish communications before the duration of Geas runs out, it will come back into effect.

However, in that same quote from Crawford, he notes that there isn't a hard rule here. Your DM could just as easily interpret it as "it keeps following your orders" or "the spell is canceled". I'd suggest talking to your DM and figuring out beforehand how this will work if you plan to use this tactic in-game.

  • \$\begingroup\$ I'm not sure I follow. If you were using google translate, and I told you something in Spanish which you then translated and understood, I feel like even when you close google translate you would still have some idea of what I said, even if you can not translate it to Spanish and repeat it back to me. All the more so if I had placed a magical command on you. It's not like you have a 1 second memory after all. \$\endgroup\$ – user-024673 Jan 28 '20 at 7:12
  • \$\begingroup\$ @jgn You're correct, that is a perfectly reasonable interpretation, which is why I suggest asking your DM. However, my answer was largely from a "how do the rules actually work" perspective. The second paragraph is trying to explain how the seemingly unintuitive situation could make sense, if the DM wants to go with the more strict interpretation. \$\endgroup\$ – AgentPaper Jan 29 '20 at 1:00
  • \$\begingroup\$ Geas also requires you to be able to see the target when you cast it, but it's assumed (or so I assume) that the caster doesn't need to keep looking at the target for the duration for the spell to remain in effect. So I don't see how not being able to communicate with the target after the spell is cast makes it an "invalid target" any more than not being able to see it. \$\endgroup\$ – Marq Jan 29 '20 at 15:21
  • \$\begingroup\$ @Marq I think that's different though, it says you need to see the target to cast the spell, whereas a creature not able to understand you is "unaffected". \$\endgroup\$ – AgentPaper Jan 29 '20 at 19:11
  • \$\begingroup\$ @AgentPaper My reading of the spell description is: if <the target understands> then <effect> else <no effect>. This condition is checked when the spell is cast, and it creates the effect that lasts for the duration of the spell. It's not checked continually for the spell's duration, and the effect, once created, doesn't depend on the condition continuing to be true. \$\endgroup\$ – Marq Jan 30 '20 at 10:09

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.