The implications of a certain magic item and Glyph of Warding

[Phhase]

Warning: With great power comes great responsibility! Use judiciously!

So, there's apparently a magic item from OotA called a Spell Gem.


A lapis lazuli spell gem can contain one spell from any class's spell list. You become aware of the spell when you learn the gem's properties. While holding the gem, you can cast the spell from it as an action if you know the spell or if the spell is on your class's spell list. Doing so doesn't require any components, and doesn't require attunement. The spell then disappears from the gem.

A lapis lazuli spell gem can store up to 1st level spells. Spells cast from the spell gem have a save DC of 13 and an attack bonus of +5.

You can imbue the gem with a spell if you're attuned to it and it's empty. To do so, you cast the spell while holding the gem. The spell is stored in the gem instead of having any effect. Casting the spell must require either 1 action or 1 minute or longer, and the spell's level must be no higher than the gem's maximum. IF the spell belongs to the school of abjuration and requires material components that are consumed, you must provide them, but they can be worth half as much as normal.

Once imbued with a spell, the gem can't be imbued again until the next dawn.


There is a gem variant for each spell level. So, pretty much like a re-useable scroll, right? Look a little closer. No matter how long the casting time of the spell you invest in the Gem (as long as it isn't a bonus action or reaction), you cast it from the gem as an action. And you don't need to be attuned to activate it, only to invest a spell.

Now, consider the Spell Glyph version of the spell Glyph of Warding. If you store a spell that requires Concentration, well, it doesn't. Normally, this would be balanced-ish, given it's quite impractical to cast the spell in combat.

'Cept now there's an item to shorten that casting time. If you store a Spell Glyph in the Gem, it's only 1 action to cast out. And if you cast it beneath you or an enemy's feet with the trigger condition "Now", well....congratulatio!

You've broken Concentration!

Oh, and just as extra gravy atop the icing, since Glyph of Warding is an abjuration, you only need half of the components! It's almost like this is the intended use...

[Dork_Forge]

I'm not sure this works at all, by all indications you aren't casting the spell yourself (you're using the gems modifier and DC), and to use a spell glyph you cast it when you cast the glyph, which it doesn't seem you are. The infusing property doesn't sound like a ring of spell Storing where you cast the spell into it either, so I just don't see this working and if it did RAW it would surely but shut down by a DM.

[MaxWilson]

That's an interesting point, but... personally I find the idea of casting a spell without using concentration less exciting than casting Planar Binding or Symbol with an action during combat.

I can't remember if the DC is always fixed at DC 13 or if it also goes up with increasing spell gem rarity, but even if it stays at 13, Symbol of Insanity is still an incredibly strong spell. (Especially if you've got a Bend Luck sorcerer in the party.)

In any case, I think this gem is a little too broken for my tastes, and I wouldn't feature one in my games.

[Contrast]

I can't remember if the DC is always fixed at DC 13 or if it also goes up with increasing spell gem rarity

1st and 2nd levels and DC13, 3rd and 4th and DC15, 5th and 6th are DC17 and 9th is DC19.


In any case, I think this gem is a little too broken for my tastes, and I wouldn't feature one in my games.

Seems sensible. That said, if they're in OotA then presumably they're available in AL though. Is there actually one higher than the 1st level one as loot anywhere though or did they just include higher level versions as a matter of principle? If you can't actually find some anywhere, problem solved :smallbiggrin:

[Phhase]

That's an interesting point, but... personally I find the idea of casting a spell without using concentration less exciting than casting Planar Binding or Symbol with an action during combat.

That's fair. This is hardly the only powerful use for a Gem.


In any case, I think this gem is a little too broken for my tastes, and I wouldn't feature one in my games.
Pfff, ain't noone gonna find fault with that, given the post I made =P.

I'm not sure this works at all, by all indications you aren't casting the spell yourself (you're using the gems modifier and DC), and to use a spell glyph you cast it when you cast the glyph, which it doesn't seem you are. The infusing property doesn't sound like a ring of spell Storing where you cast the spell into it either, so I just don't see this working and if it did RAW it would surely but shut down by a DM.

Text of the Gem: "To do so, you cast the spell while holding the gem. The spell [that you just cast] is stored in the gem instead of having any effect."

Text of Glyph: "You can store a prepared spell of 3rd level or lower in the glyph by casting it as part of creating the glyph."

While the wording is somewhat ambiguous, it looks to me technically possible to store a spell glyph in the gem, since it doesn't seem to be considered a separate action.

Oh, and apropos of gems and Concentration, does crushing an Elemental Gem to summon an elemental require your Concentration?

[JackPhoenix]

you cast[/B] the spell while holding the gem. The spell [that you just cast] is stored in the gem instead of having any effect."

Text of Glyph: "You can store a prepared spell of 3rd level or lower in the glyph by casting it as part of creating the glyph."

You aren't creating the glyph when you're storing the spell to create it into the gem.

[MaxWilson]

You aren't creating the glyph when you're storing the spell to create it into the gem.

I believe you misunderstand the proposal. The proposal is to store a Glyph of Warding in a gem, and then at some future time period to:

(1) Cast Glyph of Warding with a trigger time of "now!" or similar,
(2) Cast some other Glyph-compatible spell like Wall of Force as part of #1,
(3) Watch enemy get captured in a Wall of Force, and then on some subsequent round
(4) Cast some other spell with your concentration.

In short, you are creating the glyph as part of #1, but it's not when you store it in the gem, it's when you take it out.

[Chronos]

I've always suspected that there are certain things that made it into the rulebooks only because the writer of the rulebook wanted something overpowered for their own personal character, and so snuck it past the editor so they could then say "Look, it's published, I'm allowed to do this!". This looks like another case of that.

[Callak_Remier]

I believe you misunderstand the proposal. The proposal is to store a Glyph of Warding in a gem, and then at some future time period to:

(1) Cast Glyph of Warding with a trigger time of "now!" or similar,
(2) Cast some other Glyph-compatible spell like Wall of Force as part of #1,
(3) Watch enemy get captured in a Wall of Force, and then on some subsequent round
(4) Cast some other spell with your concentration.

In short, you are creating the glyph as part of #1, but it's not when you store it in the gem, it's when you take it out.

Since when does casting a spell into a Glyph of Warding remove the concentration requirement? Where does it say in the books it does that?

[JackPhoenix]

I believe you misunderstand the proposal. The proposal is to store a Glyph of Warding in a gem, and then at some future time period to:

*snip*

In short, you are creating the glyph as part of #1, but it's not when you store it in the gem, it's when you take it out.

Yeah, I haven't read the spell gem's description, and instead based my response on Dork Forge's post, which claims you aren't casting the spell when you use the gem. That's not true, you still cast the spell, it's just sourced from the gem and uses set DC.

[Dimers]

Since when does casting a spell into a Glyph of Warding remove the concentration requirement? Where does it say in the books it does that?

Last sentence of the Spell Glyph paragraph. "If the spell requires concentration, it lasts until the end of its full duration."

[Phhase]

Since when does casting a spell into a Glyph of Warding remove the concentration requirement? Where does it say in the books it does that?


Spell Glyph.

You can store a prepared spell of 3rd level or lower in the glyph by casting it as part of creating the glyph. The spell must target a single creature or an area. The spell being stored has no immediate effect when cast in this way. When the glyph is triggered, the stored spell is cast. If the spell has a target, it targets the creature that triggered the glyph. If the spell affects an area, the area is centered on that creature. If the spell summons hostile creatures or creates harmful objects or traps, they appear as close as possible to the intruder and attack it. If the spell requires concentration, it lasts until the end of its full duration.


That, and the fact that it's an autonomous defense that you can be any distance away from, and it remains functional. There's a Dungeon Dudes video (https://www.youtube.com/watch?v=oQBmtgU4d2g) with a segment about using Glyph in this way as well (4:30 - 10:00).

[micahaphone]

The module also describes that the deep gnome city that manufactures these spell gems has some placed in defenses of the main/only entrance, containing Cloudkill or similar, and put into the wall with sovereign glue, with a certain trigger to auto cast, I think a command word. I'm AFB, but will check the first bits of the Blindenstone chapter when I get back home