Seastars with high AC - 5e idea?

[Cleon]

Shed Arms. Whenever the giant brittle star takes at least ## damage at one time from an attack that required a Melee or Ranged Attack roll or if the brittle star is grappled by a creature that is Large size and/or possesses a Strength of ## or higher, roll a d## to determine what happens.

01-##: Nothing else happens.
##-##: The attacker makes a DC ## check (Strength for weapon hits, spellcasting ability for magic hits). If they succeed, one arm is severed from the brittle star if it has any arms left.
##-##: One arm is severed from the brittle star if it has any arms left, but the brittle star takes half damage from the attack that severed the arm.

In addition, if a giant brittle star is threatened or attacked by a creature larger than itself, or its hit points are reduced to ## of fewer, it can attempt to deliberately tear off an arm. The brittle star makes a DC ## Strength check and severs one of its own arms if it succeeds.
 A severed arm flops and writhes about for #d# rounds as it dies. The arm is unable to attack or grapple and has a speed of 5 feet. The brittle star has no control over its severed arms.
 A giant brittle star's speed is reduced to 15 ft. if it loses one or two arms, 10 ft. if it loses three and 5 feet if it loses four. If it loses all five arms it has a speed of 0 feet.
 If the brittle star finishes a long rest its arm stumps regrows enough to remove one "arm's worth" of speed reduction, so it has speed 20 ft. with one lost arms, 15 ft. with two or three lost arms, 10 ft. with four lost arms, and 5 ft. if is has lost all five arms. The brittle star regains its speed and arm attacks when its Regrowth trait replaces the lost arms.

Option: A giant brittle star with a shortened, partially regrown arm might be able to attack with it, but the arm attack will have a 5 ft. reach or 10 ft. reach instead of the 15 ft. reach of a full length arm.

Hmm, I quite like the outline of that. It covers pretty much everything I fancied.

While it's a trifle overcomplicated for 5E, that pretty much applies to the whole monster. (plus I have a tendency to add elaborations onto elaborations as I write monsters stats).

So it needs some ## values:

1. Amount of damage to risk severing from attacker's blow.
2. Minimum Strength to sever.
3. Dice distribution for table.
4. DC for auto-disarmament.

Any preferences?

 

[Casimir Liber]

Complicated is good. Especially if not a 1st level critter so players are more familiar with rules. Okay yeah this looks good - rather than percentile dice for inital table do you want to just do 1-2/3-4/5-6?

Say, DC 13 to sever own arm? (DC 15 (difficult) - 2 for proficiency?)

 

[Cleon]

Complicated is good. Especially if not a 1st level critter so players are more familiar with rules. Okay yeah this looks good - rather than percentile dice for inital table do you want to just do 1-2/3-4/5-6?

Yes, I was thinking a single low faceted die. Either d6 or d10.

1-2/3-4/5-6 was one of the possibilities I mused about, so we might as well use it.

Say, DC 13 to sever own arm? (DC 15 (difficult) - 2 for proficiency?)

It's got Strength +2 remember so that's a 50/50 chance. Is that enough for you?

I was thinking maybe DC 10 for a 65% chance of success.

Alternatively, we could just let it do it automatically rather than have to roll for it.

 

[Casimir Liber]

Yeah..I think d6 is best

Yeah could make it automatic - or DC10. Not fussed really. Could argue either way and happy with either,

 

[Cleon]

Yeah..I think d6 is best

Yeah could make it automatic - or DC10. Not fussed really. Could argue either way and happy with either,

Upon reflection, I think automatic makes more sense.

So instead of:

In addition, if a giant brittle star is threatened or attacked by a creature larger than itself, or its hit points are reduced to ## of fewer, it can attempt to deliberately tear off an arm. The brittle star makes a DC 10 Strength check and severs one of its own arms if it succeeds.​

How about:

In addition, if a giant brittle star is threatened or attacked by a creature larger than itself, or its hit points are reduced to ## of fewer, it can choose to deliberately tear off one of its own arms as a reaction. This automatically severs an arm.​

That leaves the HP thresholds, STR minimum and save DC.

The Brittle Star has 42 hp and 5 arms, so maybe 8 hit points for a blow mighty enough to snap off an arm and 20 hit points for it feeling threatened enough to teat an arm off as a distraction?

If we want there to be a good chance of it losing most of its limbs in a combat we'd want to lower the threshold to, say 5 hit points for a potentially limb-severing blow. However, it's arm attacks do that damage 50% of the time which seems a bit too fragile.

I'm presuming the save to resist dismemberment is CON-based, which'd make it DC 13 or 15.

For the minimum Strength for a grappler to possibly tear off an arm, I was thinking STR 16 or 18. High enough it'd take a strong humanoid to do it, but not unlikely for an attacker to qualify.

Which of those suits you better?

 

[Casimir Liber]

STR 18 - the chitinous material should make it a real challenge to tear off an arm.

save to resist dismenmberment DC 13

8 hp to sever an arm (5hp too easy I think), 20 to feel threatened (or Bloodied - i.e. half hp??)

 

[Cleon]

STR 18 - the chitinous material should make it a real challenge to tear off an arm.

save to resist dismenmberment DC 13

The armor's calcified not chitinous. Chemically it's the same as an oyster's shell not a beetle's carapace.

Oh and it's a check to dismember, not a save.

Unfortunately I prefer them the other way around - STR 16 and DC 15.

How about using one of each? STR 18 and DC 15.

8 hp to sever an arm (5hp too easy I think), 20 to feel threatened (or Bloodied - i.e. half hp??)

That I can agree!

 

[Casimir Liber]

The armor's calcified not chitinous.....

Dang, me being sloppy with my adjectives again...ok. Alright STR 18 and DC 15 then

 

[Cleon]

Dang, me being sloppy with my adjectives again...ok. Alright STR 18 and DC 15 then

Come to think of it, the proper adjective is calcareous not calcified. The latter means "transformed into limey/chalky material" while the former is "composed in limey/chalky material."

Sounds like we've made all the decisions on Shed Arms but I don't feel like updating the Enworld draft today.

Will get around to it eventually…

 

[Casimir Liber]

take yer time...I'll follow yer lead....