D&D (2024) Undersized Performance from Gargantuan Monsters?

[Chaltab]

The image of the Tarrasque in the Monster Manual (2025) would indicate that it would be impossible to even attack the Tarrasque with a melee weapon unless you were basically in one of the squares it occupies. The reason it's reach isn't longer is that it would basically have to double over like a person touching their toes to strike at someone.

The tail is interesting. The tarrasque's body is so wide that the length of the tail would be little help in attacking creatures in front of the tarrasque, but I could see giving it a special Legendary Action where it can abruptly spin and attack a target behind it with a 50 foot reach, but disadvantage since it's unseen.

 

[Cadence]

Remember that the area of a creature isn't the space that it fills, just the space that it fights in. The Tarrasque is often depicted with a hunched posture if not actually using its front limbs to walk on, so it is unsurprising that it doesn't have a particularly long reach with them. 15 ft is only just shorter that the area it occupies -
equivalent to a human with a longsword that occupies 5 ft and can reach 5 ft.

"The tarrasque is a bipedal, prehistoric Monstrosity that stands over seventy feet tall."

A Tarrasque can kill three T-rexes in little over 10 seconds. That seems plenty dangerous.

I will agree to that The picture and description makes me think it is more doing it by being big and stompy instead of being a cuisinart using lots of hits with its legendary actions.

Which makes me want to ask, how do legendary actions interact with readied actions? Do they go off when the initiative slot comes up, or after the readied action? (In the later case, could the T-Rex group spitefully make the Tarrasque take longer to kill them by doing something like readying the action for something it wouldn't do, like run away?).

 

[pukunui]

Dragon Turtle

View attachment 398762

"Dragon turtles are mighty creatures with shells large enough to be mistaken for islands and jaws capable of snapping ships like twigs."

Bite, reach 15 ft. 23 damage.
Tail, reach 15 ft. 18 damage.

In the free rules, anyway, a resilient cart or dining room table (Large) has 27 hit points, so the siege monster lets a Tarrasque or Kraken break them with one hit... but the Dragon Turtle and Roc don't get siege monster.

For things like a stone buildings wall, "To track Hit Points for a Huge or Gargantuan object, divide it into Large or smaller sections, and track each section’s Hit Points separately. The DM determines whether destroying part of an object causes the whole thing to collapse." But it feels odd that a section of stone wall is just as strong as a resilient table or cart. Are there more rules elsewhere?

For the Kraken and Dragon Turtle (using Saltmarsh) the easily transportable 100 pound rowboat has 50 hit points and a keelboat has 100. In those cases the new rules about dividing into parts feels like it makes more sense, I guess.

Hmm. According to the 2024 PHB, galleys and warships have the highest damage threshold (20), so the dragon turtle's average bite damage of 23 is enough to overcome that threshold. However, both ships have so many hit points that it would definitely take the dragon turtle multiple bites to be able to snap them like twigs. As you say, even a rowboat with 50 hp will require at minimum two bites!

I'm also not sure if vehicles count as objects for the purposes of breaking them into smaller sections, but that would certainly make it easier for the dragon turtle to break up ships more quickly!

Maybe the dragon turtle just needs a Siege Monster trait specific to ships. (I can't see dragon turtles bothering to attack castles and such directly anyway - unless they're under water. So maybe it should just get the Siege Monster trait full stop. Same with the roc.)

 

[Worrgrendel]

So, one of the ways I have handled colossal monster attacks in the past is their melee attacks, claw/rend/tail, attack in a cone equal to their melee reach. So, lets use the Tarrasque, it’s attacks have a 15’ reach so they instead attack in a 15’ cone and can potentially hit multiple targets with one attack roll. This was to simulate that if they just swung that big ‘ol claw at a group of knights or soldiers, they’re going to take several out at a time. Tail attacks with a long reach could be especially devastating. Bites I did a little different, if the monster was especially big I gave the bite attack an area attack of a 10’ cube but most of the time it was just single target.
I’ve been mulling around with idea of these colossal monsters also being able to insta-kill low CR NPC’s. I haven’t completely worked it out but I was thinking something along the lines of NPC’s under a certain CR less than 1/5 the monster’s CR when hit make a Con save = half the damage delt by the attack. If they fail, they’re dead. If they succeed, then they take the greater of the damage delt or half their HP max. Meaning they always go down in 1 or 2 hits.

 

[Distracted DM]

For things like a stone buildings wall, "To track Hit Points for a Huge or Gargantuan object, divide it into Large or smaller sections, and track each section’s Hit Points separately. The DM determines whether destroying part of an object causes the whole thing to collapse." But it feels odd that a section of stone wall is just as strong as a resilient table or cart. Are there more rules elsewhere?

I believe the section on objects MAY have also mentioned damage thresholds in passing? "Unless you do X damage, it does nothing." Oh wait is this marked DnD General or 2024... I don't know, I seem to recall something in that vein- or I'm remembering it from A5E or something else

 

[DragonLancer]

Giant colossal monsters in D&D and Pathfinder have always been underwhelming, It's not the reach as I can understand you want the characters to get up and go toe to toe, but the damage is always pathetically weak. I remember, for example, in the 3.5 Tome of Horrors (Necromancer Games) that they had a Shipbreaker Sea Serpent which was the big enough to bite down and potentially swallow a galleon sized ship. For a creature it's size and power, the bite damage was something like 2D10+25 (don't quote me, it's a been a while) which seems nothing compared to what the creature represents. I always think such monsters need much higher damage output.