Making a Landmine Spell

[Thrasher92]

I'm trying to make a "Landmine" spell for Artificers, Sorcerers, and Wizards. Please let me know if it is too powerful, not powerful enough, or if I need to change the wording.

Landmine 1st level Evocation spell Artificer, Sorcerer, and Wizard
Casting Time: 1 Minute Range: Touch (10ft Radius Explosion) Duration: 8 Hours
Dexterity Saving Throw Fire Damage

You create an orb of fire that can be planted up to 5 feet into the ground. After being planted the mine cannot detonate for 30 seconds. After the 30 second period, whenever a creature gets within 10ft of the orb, it must make a Dexterity saving throw or take 2d6 fire damage, half damage on a successful saving throw.

At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, the damage increases by 1d6 for every slot higher than first.

[Silly Name]

From the point of view of an adventurer, this is best used to set up ambushes. If it could be made permanent, it'd be a neat magic trap for spellcasters of all sorts to protect their stuff.

I suppose the 30-second grace period is to let you and your allies get away? I'd honestly just make it so the mine doesn't trigger if it's you, and possibly giving you the ability to designate a number of "friendlies" that also don't trigger the mine. Another option is that the mine is initially "dormant", and you need to order it to activate before it can explode, but you can't recall the order.

I'd also make any creature within 10 feet of the mine save for half damage once it detonates, just to get that landmine feel a bit better.

Two rules questions: is there any way to detect the mine? Do I have to plant the mine underground, or can I leave it out in the open?

[Kane0]

Looks okay, aside from maybe it should have some way to detect that it’s there. The damage looks a bit on the low side for the setup time but on the other hand its a long duration without concentration.

Edit: wait, its one creature and not everyone in the radius when it detonates. Maybe fix that to something like ‘when creature gets within 5’, everyone within 15’ dex save or 2d6 fire damage’

You can check it against alarm, snare, cordon of arrows, glyph of warding and similar spells if you need reference points.

[KorvinStarmast]

I'm trying to make a "Landmine" spell for Artificers, Sorcerers, and Wizards. Please let me know if it is too powerful, not powerful enough, or if I need to change the wording.

Landmine 1st level Evocation spell Artificer, Sorcerer, and Wizard
Casting Time: 1 Minute Range: Touch (10ft Radius Explosion) Duration: 8 Hours
Dexterity Saving Throw Fire Damage

You create an orb of fire that can be planted up to 5 feet into the ground. After being planted the mine cannot detonate for 30 seconds. After the 30 second period, whenever a creature gets within 10ft of the orb, it must make a Dexterity saving throw or take 2d6 fire damage, half damage on a successful saving throw.

At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, the damage increases by 1d6 for every slot higher than first.
Did you compare it to the level 1 Ranger spell Snare? Similar thing ... though it's not a damage spell.

[Thrasher92]

From the point of view of an adventurer, this is best used to set up ambushes. If it could be made permanent, it'd be a neat magic trap for spellcasters of all sorts to protect their stuff.

I suppose the 30-second grace period is to let you and your allies get away? I'd honestly just make it so the mine doesn't trigger if it's you, and possibly giving you the ability to designate a number of "friendlies" that also don't trigger the mine. Another option is that the mine is initially "dormant", and you need to order it to activate before it can explode, but you can't recall the order.

I'd also make any creature within 10 feet of the mine save for half damage once it detonates, just to get that landmine feel a bit better.

Two rules questions: is there any way to detect the mine? Do I have to plant the mine underground, or can I leave it out in the open?

Well, I was thinking of making the material component a tiny clay ball, and that's what the spell is cast on. I didn't want the caster to be able to designate friendlies because that makes it a bit more powerful. I suppose you wouldn't have to bury the clay ball, you could hang it or something.

I was thinking that a successful Investigate check would reveal the spell.

[heavyfuel]

2d6 damage for a 1st level slot is pretty weak.

Yeah, you can have multiple such mines, but with the casting time and the 30 second "delay", you cannot have multiple mines in the same spot (the first mine will detonate before you finish casting the second).

Compare it to, say, Burning Hands. An extra d6 damage, can actually affect multiple targets (your spell detonates as soon as the first enemy comes close, so unless they are walking side-by-side, only one enemy takes damage), better area but worse range, no need for setup. If we assume the landmine spell makes noise, it can also be used as a pseudo-alarm spell.

The change I'd make it is that the mine only triggers if a creature is ever within 5ft, but the radius of the explosion is 10ft, so you can at least get multiple targets with it. Plus, it doesn't step on Alarm's toes too much. I'd also make it 3d6 instead of 2d6.

[Kane0]

Oh, you could also take a look at erupting earth to model the explosion rather than just a chunk of fire damage ala burning hands

[Amnestic]

I'm trying to make a "Landmine" spell for Artificers, Sorcerers, and Wizards. Please let me know if it is too powerful, not powerful enough, or if I need to change the wording.

Landmine 1st level Evocation spell Artificer, Sorcerer, and Wizard
Casting Time: 1 Minute Range: Touch (10ft Radius Explosion) Duration: 8 Hours
Dexterity Saving Throw Fire Damage

You create an orb of fire that can be planted up to 5 feet into the ground. After being planted the mine cannot detonate for 30 seconds. After the 30 second period, whenever a creature gets within 10ft of the orb, it must make a Dexterity saving throw or take 2d6 fire damage, half damage on a successful saving throw.

At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, the damage increases by 1d6 for every slot higher than first.

Three thoughts come to mind.

First: Wording could do with being cleared up on its duration - as it stands the orb can apparently keep detonating constantly for 8 hours since it doesn't say that the spell ends after the first explosion. If that's the intention, it feels wrong thematically for a 'landmine' to last for 8 hours constantly exploding.

Secondly on its size. The "threshold" for activating the mine and its explosion radius are the same, meaning you'll only ever catch a single creature with this due to how turns work. I'd either up the radius (15' or 20') of the explosion or lower the trigger radius (5'). Maybe both, even. I can understand not wanting people to have to stand on the exact spot its on.

Third, I don't know if it'd make it too wordy or if it's even something you want to do, but I think it might be neat if you could retrieve the mine undetonated and place it in a new location, if it doesn't end up going off during the fight.

[sayaijin]

I encourage you to look at the spell glyph of warding. It's a third level spell, but I think it's everything you want.

[Damon_Tor]

If you allow for "downcasting" of glyph of warding, you'd wind up with 3d8 damage when cast with a 1st level slot.

[Silly Name]

First: Wording could do with being cleared up on its duration - as it stands the orb can apparently keep detonating constantly for 8 hours since it doesn't say that the spell ends after the first explosion. If that's the intention, it feels wrong thematically for a 'landmine' to last for 8 hours constantly exploding.


The mental image of some poor sap being caught in a constant, 8-hours long explosion is morbidly hilarious, though. You may want to get some hearing protection before sitting down to watch.

[Thrasher92]

Okay, so based off of some of your suggestions this is what I have so far.

Landmine 1st level Evocation spell Artificer, Sorcerer, and Wizard
Casting Time: 1 Minute Range: Touch (10ft Radius Explosion) Duration: 8 Hours
Components: V, S, M (A Tiny ball of clay) Dexterity Saving Throw Fire Damage

You create an orb of fire that can be planted up to 5 feet into the ground, before being placed the caster can designate a number of targets up to his spellcasting modifier (minimum 1) that will not trigger the mine. After being placed the mine cannot detonate for 30 seconds. After the 30 second period, whenever a creature gets within 5ft of the orb, it and any creature with 10ft must make a Dexterity saving throw or take 3d8 fire damage, half damage on a successful saving throw. The spell ends after the first detonation.

A successful Investigation check will reveal the mine before it can detonate.

At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, the damage increases by 1d8 for every slot higher than first.



How is that? Now, I was thinking about including some wording about how someone can conceal the mine. Maybe a Survival check to hide it and the enemy would have to beat the DC made by the survival check with the Investigate check?

[heavyfuel]

How is that? Now, I was thinking about including some wording about how someone can conceal the mine. Maybe a Survival check to hide it and the enemy would have to beat the DC made by the survival check with the Investigate check?

I think it's fine. As for concealing the mine, maybe make it part of the upcasting?

Reduce damage to 3d6, and upcasting to an extra d6, but with additional effects. At 3rd level enemies have Disadvantage on their Investigation check, at 5th level the mine can only be detected by someone who can see invisible objects?

[Zhorn]

For a material component I'd say go for something from the Adventuring Gear section of the PHB. The two most similar spells for how this triggers being Cordon of Arrows and Snare, each as an 8 hour concentration free proximity spell for 8 hours, so modelling after them is a good idea.
Cordon of arrows uses 4 pieces of ammunition (arrows or crossbow bolts). With 1 gp = 20 arrows/bolts we get 4 arrows = 2 sp
Snare consumes 25 feet of rope. Hempen rope is 1 gp = 50 feet, so 25 feet = 5 sp

Now since this is an area of effect I'd aim for something more costly than 2 sp for Cordon of Arrows.
A tinderbox would be my recommendation. Costs 5 sp and is thematically related to the fuse/ignition flavour of a fire typed explosion.

As far as concealing/investigating to discern the trap, just copy Snare's wording, with the DC is set to the same as the spell's DC at the time of casting. No need to over complicate it with extra nested values.


2d6 damage for a 1st level slot is pretty weak.
For an instantaneous and single target 1st level spell, yes I'd agree, but for an aoe landmine with up to 8 hours delay I think 2d6 is more than respectable. Comparison being Cordon of Arrows is four lots of 1d6 at 2nd level, and upcasting for two additional 1d6 per slot. Going to 3d6 (or 3d8 as in Thrasher92's latest version) and as fire damage instead of weapon damage is more powerful than what Cordon of Arrows offers.
Stick with 2d6 for a 1st level spell slot to avoid power creep, and I'd also not have upcasting considering that would very quickly encroach on Glyph of Warding.

[Lunali]

I'd suggest something to limit the number of castings, either only allow 1 at a time, spellcasting bonus (min 1) or require concentration. That is, unless you want people stacking multiple instances of the spell in a location.

[stoutstien]

Why not make it a mundane adventuring gear item rather than a spell? They really aren't that complexes and spell casting is already hogging a lot of design space.

[heavyfuel]

Why not make it a mundane adventuring gear item rather than a spell? They really aren't that complexes and spell casting is already hogging a lot of design space.

And let martial characters do cool things?! Pfff, I don't think so! obvioussarcasm

[Kane0]

Why not make it a mundane adventuring gear item rather than a spell? They really aren't that complexes and spell casting is already hogging a lot of design space.

Good point. Tinker's tools + Tinderbox + Alchemist's Fire.

[Lunali]

Good point. Tinker's tools + Tinderbox + Alchemist's Fire.

You can probably skip the tinderbox, alchemist's fire ignites on contact with the air.

[Guy Lombard-O]

After the 30 second period, whenever a creature gets within 5ft of the orb, it and any creature with 10ft must make a Dexterity saving throw or take 3d8 fire damage, half damage on a successful saving throw.

Maybe try: "After the 30 second period, the first time a creature gets within 5' of the orb it springs from the ground and detonates. Any creatures within a 10' radius of the orb must make a Dexterity saving throw or take 3d8 fire damage, half damage on a successful saving throw."

Also, I think 2d6 is way more appropriate for a 1st level spell. 3d8 with a 10' radius is equivalent to a Shatter.

[Senjou]

How about spell for which casting is instantaneous but you can set up the bomb wherever you want. It would read something like:

1 level evocation

You select a point in space and you create a mine on that point. Whenever a creature step on that point it would trigger an explosion. The creature needs to make a DC Dex saving throw or take 2d6 fire damage. You can select any number of creature for which this spell would not activate. For each level above 1 you can create another mine.

[Kurt Kurageous]

I encourage you to look at the spell glyph of warding. It's a third level spell, but I think it's everything you want.

Ditto. That is the spell you are looking for, no need to make another one.