D&D 5E Tremorsense as a spell - ideas?

[Ancalagon]

So a player of mine wants to design a homebrew spell that would grant tremorsense - the idea is being a spore druids, the underground fungal filaments (the hyphae) would grant her information.

The problem is, I have no idea what level that should be at. Based on D&D beyond, there is one magical item that grants tremorsense (a legendary pick, earth-aspected), and a number of monsters that have the sense and ... that's it. Clearly it can't be as high level as True Seeing, but I would welcome any feedback, comment and considerations.

thanks!

 

[Hawk Diesel]

I'd say 3rd or 4th level is appropriate, given the Darkvision spell is 2nd level. Range 60ft, one hour duration, no concentration, upcast to target additional creatures. At least, that's how I'd do it.

 

[Quickleaf]

I see Tremorsense as having the most in common with a ring of x-ray vision (a rare magic item), since the main benefit is perceiving a creature through walls/obstacles. Both can still be thwarted by a stealthy creature if the conditions are right. Unlike the ring, Tremorsense doesn't detect flying creatures or creatures not "in contact with the same ground." The DMG guideline for when PCs "should" acquire a rare item is 5th level or higher... which would mean we're looking at a 3rd level spell as a baseline minimum.

It's worth noting that the One D&D Playtest gives dwarves a Tremorsense feature, which requires being in contact with stone, and can be used a # times / long rest = prof modifier, requiring a Bonus Action with a range of 60 ft and lasting 10 minutes. In other words, it's a LOT like the Darkvision spell, just with a shorter duration (and no sharing the love). This suggests to me the value of Tremorsense is not perceived by the designers as being worth a 5th+ level spell (such as Scrying), since race traits tend to be in the lower power ranges (e.g. the various traits granting resistance correspond pretty close to Protection from Energy, a 3rd level spell).

I agree it's going to be a 3rd or 4th level spell, depending how you swing it.

 

[aco175]

Its worth partly depends on how much you are in a dungeon where everything is touching the ground. If it is a self only spell or can it be cast on others? Is it designed for a certain instance such as one encounter or to bypass one obstacle, or is it meant to bypass a torch? Do you want it like mage armor where you basically just cross off a spell slot.

I could see it as a 2nd level spell with a 10 minute duration, no concentration. Upcast to make the duration 1 hour or grant 1 additional person the ability.

 

[LordEntrails]

I would have thought 4th or 5th. But that's going to depend upon target and duration. i.e. can you cast it on others (yes...) and does it last 10 minutes, 8 hours or all day? I assume it's not concentration.

In most ways it's not as good as Truesight, but mostly better than darkvision. About on par with blindsight, but not equivalent in some situations.

How much is it going to impact your game? Do other characters already have other vision types? If the impact is minimal, then I could see a 3rd level spell for a 10 minute duration. 4th for 8 or 24 hours.

 

[Tonguez]

In most ways it's not as good as Truesight, but mostly better than darkvision. About on par with blindsight, but not equivalent in some situations.

blindsight says that “The target creature gains sensitivity to vibrations“ so personally I’d rule that OPs Spore Druids have the ability to use blindsight through the ground via their hyphae up to 30ft

 

[LordEntrails]

blindsight says that “The target creature gains sensitivity to vibrations“ so personally I’d rule that OPs Spore Druids have the ability to use blindsight through the ground via their hyphae up to 30ft

For me those vibrations are air related, and not ground related. So useful against flying creatures, but not burrowing ones. Where tremorsense is useful for those burrowing or touching a solid surface, not flying.

 

[NotAYakk]

This kind of spell should require concentration. It is an extraordinary sense that cannot be gained through most other means.

But I would probably roll it in with another effect, because completely separable magical effects are boring.

Earthen Integration - Concentration (1 hour), self, 2nd level druid spell
You integrate your body with the ground you are walking on. So long as you are standing on earth or natural stone you gain these benefits:

• Tremorsense 30'
• If hit by an attack or fail a constitution or dexterity saving throw, you can expend a reaction to gain a +5 bonus to your AC or to your saving throw.
• As an action, you can make a melee spell attack with a 15' reach by having the ground lash out at a foe. It deals 1d12+2 bludgeoning damage on a hit and the target is grabbed (escape DC is your spell save DC) by the ground while within 15' of you.
• You gain 5 temporary HP at the start of your turn. If you are no longer touching the ground you lose these temporary HP.

At higher levels:
The temporary HP is increased by 5 points for every spell level about 2nd, and your melee spell attack damage is increased by 1.
You can make up to 1/2 the spell level (rounded down) attacks as an action.

Like, something a bit fun that also includes tremorsense.

 

[Tonguez]

For me those vibrations are air related, and not ground related. So useful against flying creatures, but not burrowing ones. Where tremorsense is useful for those burrowing or touching a solid surface, not flying.

Yeah I agree, which is why I’d make a ground based version specific to Spore Druids and similar types as a specialist use of the spell-ability.

Switching the detects ‘flying creatures‘ to detects “burrowing creatures” gives enough balance imho

personally I’d also make it concentration, but heh