RAW/RAI “Burrowing” Questions

TarodNet Thanks for digging that ! The Cave Badger: is a prime example of a monster that leaves tunnels behind when it burrows through sand, earth, mud, or ice.

Quote from Plaguescarred >>

TarodNet Thanks for digging that ! The Cave Badger: is a prime example of a monster that leaves tunnels behind when it burrows through sand, earth, mud, or ice.

 However, that's in an adventure, and the giant badger (which I expect is mostly the same, it's the same CR and size) doesn't have that trait.

Quote from TarodNet >>

Quote from MaximusArael020>>

Quote from TarodNet>>

I also think it's as Plaguescarred explains, and there is at least one other example where the tunnel is created only for the specific mentioned terrains.

Aurumvorax and Aurumvorax Den Leader, from Journeys through the Radiant Citadel: "The aurumvorax can burrow through solid rock and metal at half its burrowing speed and leaves a 5-foot-diameter tunnel in its wake."

 I appreciate the additional example, however I don't feel this is actually any clearer, as the ambiguity is the same. It is still the same template: "Tunneler. The [creature] can burrow through solid rock and metal at half its Burrow Speed and leaves a [number]-foot-diameter tunnel in its wake."

It's the same, just with "and metal" added to the otherwise prohibited materials the creature can burrow through. [...]

 Happy to help :) Or trying to :D

And I think I found another interesting example! After reading Pantagruel666's reply, I remembered from Out of the Abyss, the Cave Badger:

Speed 30 ft., burrow 15 ft. (when they burrow, they leave tunnels behind them)

 

 Thanks! You're always helpful. I almost tagged you in the original question, because I know you always bring the receipts and have a lot of knowledge of the rules and resources.

This is an interesting example for sure!

Thank you so much for your words, Maximus Arael. I also learn a lot from you and the rest of the players and DMs here, so thank you as well for sharing your insights and Expertise on D&D :)

Quote from Pantagruel666 >>

Quote from Plaguescarred >>

TarodNet Thanks for digging that ! The Cave Badger: is a prime example of a monster that leaves tunnels behind when it burrows through sand, earth, mud, or ice.

 However, that's in an adventure, and the giant badger (which I expect is mostly the same, it's the same CR and size) doesn't have that trait.

 The Cave Badger is a Giant Badger with different AC, Special Senses and Traits.

As Out of the Abyss say;

Cave Badgers

The svirfneblin use these beasts as part of their digging workforce. Cave badgers are giant badgers with AC 12 (natural armor), tremorsense out to a range of 60 feet, and a burrowing speed of 15 feet. When they burrow, they leave tunnels behind them.

Quote from Plaguescarred >>

 The Cave Badger is a Giant Badger with different AC, Special Senses and Traits.

I still have no idea why a normal badger doesn't leave a hole behind it, all real world burrowing animals leave holes. If the intent is for burrowing creatures to behave in an intuitive way, leaving a tunnel should really be the default -- only creatures with a special trait (such as earth glide) don't leave a hole -- but it's up to the DM how stable that hole is. 

I would assume real world animals and even humans can dig holes and tunnels, but not while moving with a special speed and therefore at a much slower rate.

TBH i don't think any real world animal can burrow a 15 or 30 foot long tunnels in 6 seconds so Burrowing Speed is not really comparable.

Quote from Plaguescarred >>

I would assume real world animals and even humans can dig holes and tunnels, but not while moving with a special speed and therefore at a much slower rate.

 Sure, burrow speed is cinematically fast, but it's still supposed to represent something with at least a veneer of plausibility, and unless a creature is incorporeal, it can't move through an object without making a creature-sized hole, so the question is whether something fills the hole up behind them.

Quote from Pantagruel666 >>

Quote from Plaguescarred >>

I would assume real world animals and even humans can dig holes and tunnels, but not while moving with a special speed and therefore at a much slower rate.

 Sure, burrow speed is cinematically fast, but it's still supposed to represent something with at least a veneer of plausibility, and unless a creature is incorporeal, it can't move through an object without making a creature-sized hole, so the question is whether something fills the hole up behind them.

 Yes.

And when the thing is 70 feet tall like a Tarrasque . . . and burrows . . . its basically creating an entire underground cave network in minutes.  It doesn't make tons of sense to me why it would not leave a tunnel.  But mechanically, its easier for a DM if it doesn't.  I might house rule that it does leave a tunnel of loose dirt but is too dangerous to travel and eventually just gets filled in with mud at the next rain.

Quote from Pantagruel666 >>

Quote from Plaguescarred >>

I would assume real world animals and even humans can dig holes and tunnels, but not while moving with a special speed and therefore at a much slower rate.

 Sure, burrow speed is cinematically fast, but it's still supposed to represent something with at least a veneer of plausibility, and unless a creature is incorporeal, it can't move through an object without making a creature-sized hole, so the question is whether something fills the hole up behind them.

It's the difference between digging a tunnel slowly, intending it to remain afterward, and plowing through earth as quickly as you can with the "tunnel" collapsing behind you 

Quote from AntonSirius >>

It's the difference between digging a tunnel slowly, intending it to remain afterward, and plowing through earth as quickly as you can with the "tunnel" collapsing behind you 

Digging quickly without making an effort to clear out the rubble just leaves a tunnel that's full of rubble.

From a mechanics perspective, the important point is that a burrowing creature cannot grab someone, pull them underground, and leave them trapped, but any of "they can't pull people underground at all", "they can pull people underground but it leaves a hole so if they escape they can climb out", and "they can pull people underground but at worst they're buried in soft materials and can pull themselves out" is an acceptable rule.

Quote from Pantagruel666 >>

I'm not convinced that a creature without tunneler doesn't leave a hole behind, because SAC has a problem of comparing two creatures that both have special traits (Tunneler and Earth Glide), and Earth Glide specifically says "the elemental doesn’t disturb the material it moves through".

This implies that a creature with Burrow speed that does not have earth glide 'disturbs' the material it moves through. This is, of course, undefined, but we do have an example of a mundane creature that has a burrow speed and has no traits related to leaving a tunnel behind: the badger. If we assume that monsters with a burrow speed work in the same way as normal creatures with a burrow speed, the way it would be expected to work is:

1. A burrowing creature that lacks a special trait leaves at least a temporary hole.
2. This hole may collapse, depending on the material.

 I understand your reasoning here.

Mechanically, for a monster the size of a Tarrasque . . . I am debating what this would look like.  I imagine it might create a tunnel network and I would have to have an "underground map" of the battlefield.  If I did that, I am unsure how to handle the "cave in" situation.  It seems like it would be a great way to TPK a party on accident if I created a mechanic and stuck to it.  On the other hand, I could also simply describe a sort of "quicksand" hole and treat it as such, rather than a tunnel.  If a character fell into it, maybe a simple Athletics or Acrobatics check?

I kind of like the idea of the Tarrasque creating a tunnel network that grows over time.  It would just be hard to map this.  Theater of the mind could work I suppose.  It is hard to say what the party will decide to do.  They might avoid such a tunnel.  They might jump right in and force me to get creative.

Thank you everyone for your insight . . . it's been great to read.