As an Unseen Servant is "shapeless", its size is not defined. The Alarm spell, however, relies on a creature's size (Tiny or larger) to be activated. Therefore, I'm not sure if an Unseen Servant, when commanded to walk through a location containing an Alarm, would trigger said Alarm or not. I would think it does, but I might be wrong (maybe the Unseen Servant's size value is "null"), hence the question.

Also, one of the two ways to receive an Alarm notification is mental. I'm wondering whether that notification can be customized, so that if the Unseen Servant crosses through Alarm #1, you can get a different "ping" than for Alarm #2. Again, I would think so, but it's better to verify (maybe it's always the same sound regardless).

Finally, I'm almost certain that if you go back and forth through an Alarm zone, you will repetitively get the "ping", but I just want to be 100% sure.

  • \$\begingroup\$ Alrighty. But as found out in another (now deleted) question, it's possible for an Unseen Servant to hold a living, unconscious or zombified Tiny+ creature to trigger the Alarm properly. Crawford seems to accept the unconscious idea : "A corpse is an object. An unconscious creature is a creature. " \$\endgroup\$ – Gael L Jul 5 '17 at 16:53
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    \$\begingroup\$ Also note that an Unseen Servant has a strength of 2 - that's a carrying capacity of 30lbs. \$\endgroup\$ – NautArch Jul 5 '17 at 17:00
  • \$\begingroup\$ As long as the Tiny creature is not obese, it works out. \$\endgroup\$ – Gael L Jul 5 '17 at 17:03
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    \$\begingroup\$ Out of curiosity... Why do you want to have the unseen Servant trigger an alarm? \$\endgroup\$ – NautArch Jul 5 '17 at 17:08
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    \$\begingroup\$ Okay, just be aware that the servant can't be further than 60' from you and it can only move 15'/command (cooking may or may not be considered 'simple', ask your DM). \$\endgroup\$ – NautArch Jul 5 '17 at 17:20


Unfortunately, the requirements for Alarm are clear in the spell description (as you stated) with the trigger requiring a Tiny or Larger creature. Because unseen servant has no form, it has no form to trigger the Alarm (just like an illusion wouldn't trigger the alarm, either.)

As for customization of Alarm - that is up to discussing that with your DM and covers both the alert and the inclusion of Unseen Servant as a potential trigger.

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    \$\begingroup\$ A thief can use unseen servant to walk into your camp and take anything not secured... \$\endgroup\$ – Protonflux Jul 6 '17 at 11:18


Alarm (PHB p.211, emphasis mine):

Until the spell ends, an alarm alerts you whenever a Tiny or larger creature touches or enters the warded area.

Unseen Servant (PHB p.284, emphasis mine):

This spell creates an invisible, mindless, shapeless force that performs simple tasks at your command until the spell ends.

Alarm reacts to creatures; Unseen servant doesn't create a creature, so it can't trigger Alarm. Note that this has nothing to do with size.

  • \$\begingroup\$ Oh. Dammit. Right. Creature. Forgot about that. But...... If an Unseen Servant is holding an insect, then maybe... \$\endgroup\$ – Gael L Jul 5 '17 at 16:34
  • \$\begingroup\$ @Mindwin Including unconscious ones ? \$\endgroup\$ – Gael L Jul 7 '17 at 2:59
  • \$\begingroup\$ @Mindwin I seem to be getting on your nerves, which is not my intention. In hindsight, the real question I should have asked is "how can you know when an Unseen Servant finishes a task if you don't see/hear him?" Then people would have suggested probably better solutions than the one I'm attempting to validate above. I am deeply sorry for all the time you lost in dealing with me. But I wish you a good day. \$\endgroup\$ – Gael L Jul 7 '17 at 14:06
  • \$\begingroup\$ @GaelL Probably not. Had you got on my nerves, I'd have walked away. I checked your profile, you are new to the stack as a whole, so I'd want to give you some pointers: the stack is bad for back-and-forth conversations like what you are trying to have. This is not a forum. You formulate a question, then get answers. Read more from one of our moderators rpg.meta.stackexchange.com/a/7271/11402 \$\endgroup\$ – Mindwin Jul 7 '17 at 15:14

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