What CR should this be?

[Rift_Wolf]

I had the idea of making a Shambling Mound home to a nest (6-8) shocker lizards, which have learnt to zap their home to make it stronger so they can feed off whatever it kills.
The Shockers would be CR2 each, and the Shambling Mound is CR6. The shockers would have cover from direct attacks due to their nest, and if severely harmed would burrow deeper in to gain total concealment. They would still be succeptible to area effects, however. The Shambling Mound, however, would be gaining 3 to 4d4 of Constitution per turn (With a pair of shockers using their lethal shock against it), which could give it between 8 to 48 hit points a turn for a nest of six, and between 16 to 64 for a nest of eight until the lizards are killed.
I think the CR for a nest of six would be CR8, and the nest of eight would be CR10. Would this be about right? Or should I add more to the CR on account of the potentially insane amount of hit points such a combination could accrue?

[Lord Lorac Silvanos]

The temporary increase in constitution would overlap instead of stacking. You would only use the best d4 roll to determine the temporary constitution increase.

I am also uncertain to whether a Shambler would be keen on having a group of lizards living in it, and how they are accommodated within its body.

[Rift_Wolf]

A shambling mound is a living plant; it'd be the same as creatures living inside hollows in a tree or in the spaces in a hedge. It wouldn't mind the occasional zap of electricity, and would accept its new lodgers in the symbiotic way animals generally do.
As for not stacking... DAMN I'll have to go back to the drawing board for new methods of inventive evil!

[Lord Lorac Silvanos]

Yes, except that it is a creature and not a hollow tree. I am not sure there are any room for moving around inside its body.



If you are the DM you can of course just alter its appearance to fit your image. I think the idea has some merit and it seems like the way encounters will be created in 4th edition.


But who wants to live in rotting vegetation anyway.

Shambling mounds, also called shamblers, appear to be heaps of rotting vegetation. They are actually intelligent, carnivorous plants.

[KIDS]

This idea of a symbiosis is a genius concept; great job there. Since constitution bonus indeed overlaps, I'd say that plant with four or so lizards would be CR 8, it seems fitting. Plus your druids or nature types will be fascinated with the concept.

For how Shambling Mound carries them, maybe they chewed in a bit? (gross) Or it has grown something like a kangaroo's pouch? Both seem quite reasonable options.

[SoD]

With CR, tecnically the CR would be the same, although, due to useful tactics, you should award extra XP for the higher challenge. You wouldn't do this if the extra challenge is due to poor player/good DM rolls, but if the opponant uses tactics/terrain well or similar things, give extra XP. What's worth more XP? A dozen orcs charging at you from across the plains, or a dozen orcs on the other side of a bridge that you have to cross one by one, hiding behind a barricade and only poking their heads over to fire their crossbows, giving them 9/10ths cover, and one of them holding the rope for the bridge, ready to let go and send the bridge plummeting downwards into whateverness? Tecnically, the same CR, whatever a dozen orcs would be. But what's worth more XP? Assuming that they're all 1st level warriors, give them standard treasure. But award extra XP, anywhere from 110% of normal to 1000% of normal, depending on the challenge. OK, maybe that's a tad over the top, but you get the idea.

Looking at symbiotic relationships, you could potentially throw in shocker lizard/shambling mound with the symbiotic template from Savage Species. It would count as a single monster. There's nowhere saying that you can throw in multiple 'parasites' on the same 'host'.

[Rift_Wolf]

This idea of a symbiosis is a genius concept; great job there. Since constitution bonus indeed overlaps, I'd say that plant with four or so lizards would be CR 8, it seems fitting. Plus your druids or nature types will be fascinated with the concept.

For how Shambling Mound carries them, maybe they chewed in a bit? (gross) Or it has grown something like a kangaroo's pouch? Both seem quite reasonable options.

Nature's full of symbiotic relationships like this, so yeah a druid would find the relationship fascinating. I came up with the idea while trying to come up with new and inventive encounters (Another was a clan of ancient Dust Mephits that had lost their extraplanar subtype and lived as desert nomads)
My general idea for it was not so much that the Shambler was a solid entity, more like a bush; it had the central trunk with the branches coming off it, but around that was a lot of free space that could be occupied.

[Azerian Kelimon]

Hmm...


If the CON bonus overlaps, could this mean that every time the lizards score a higher roll on the CON bonus, the mound gains ALL the new points, or only those above the previous roll? If the case is the first, the mound is now tremendously more powerful, 2 or 3, maybe 4 CR's higher. If it's the second, I'd say only 1 or 2 CR's.

[daggaz]

only those above. thats the definition of overlapping.

I gotta say, kudos to a really cool idea. And yeah, I can definitely see there being room inside of its body for this, despite the picture. Its a an animated mass of vegetation, there could easily be gaps and stuff. It doesnt have to be solid like a human or a cow or whatever.. I imagine vines and stuff sliding around over eachother etc..

[brian c]

Hmm...


If the CON bonus overlaps, could this mean that every time the lizards score a higher roll on the CON bonus, the mound gains ALL the new points, or only those above the previous roll? If the case is the first, the mound is now tremendously more powerful, 2 or 3, maybe 4 CR's higher. If it's the second, I'd say only 1 or 2 CR's.

You gain hitpoints based on what your improvement in Con is. If the shambler currently has +4 Con and then gets zapped and +6 is rolled, it only gains 1 hp/HD, because it's hgher by 2 Con. If there's another zap for +5 con, it has no effect.

[Sstoopidtallkid]

Except that when the +6 bonus wears off, it still has a +5 for one more round. That tracking could get tricky.

[Rift_Wolf]

Except that when the +6 bonus wears off, it still has a +5 for one more round. That tracking could get tricky.

Temporary constitution lasts one hour, not a round.

Thanks for the kudos everyone, I'll have to go back to my sadistic drawing board and come up with another similar relationship (The best I can do right now is a flesh golem/digester working in unison, and I hate myself for even thinking it).

In the meantime, would a homebrew shambler which gains 1d2hp per electric attack as temporary hitpoints (Lasting one hour) too destructive a concept in my evil hands?

[Azerian Kelimon]

Nah. It's like a minor shapeshift githyanki, though maybe less powerful. THAT would be an encounter of CR 3 or 4 higher.

[Mad Wizard]

Wait, the Shambling Mound's Con bonuses don't stack? I swear I've seen several builds on the Wizards boards that make use of it stacking for massive HP. Was there something that I was missing there that isn't here?

[Lord Lorac Silvanos]

Temporary constitution lasts one hour, not a round.

I think he was referring to the fact that you only lose one temporary point of CON every hour, you do not lose all of them.

As a side note, it is 1d4, not 1d6.

In the meantime, would a homebrew shambler which gains 1d2hp per electric attack as temporary hitpoints (Lasting one hour) too destructive a concept in my evil hands?

No, I think that would be reasonable and it fits well with the fluff. Just note that temporary HPs also overlap.
But it is easy to amend, just grant them as non-temporary as long as they are below normal max.

Spoiler

Show

Do temporary hit points from two applications of the
same effect stack? What about from different effects? If I
have temporary hit points from multiple sources, how
should I apply damage?

Temporary hit points from two applications of the same
effect don’t stack; instead, the highest number of temporary hit
points applies in place of all others. Temporary hit points from
different sources stack, but you must keep track of them
separately.
For example, imagine a character who gained 15 temporary
hit points from an aid spell. After taking 8 points of damage,
she has 7 temporary hit points left from the spell. If another aid
spell were cast on the same character granting 12 temporary hit
points, this total would replace the other spell’s total, meaning
the character would now have 12 temporary hit points (rather
than 19). If the character then cast false life on herself, she
would add the full benefit of that spell to the temporary hit
points from the aid spell.
This also applies to temporary hit points gained from
energy drain and similar special abilities. Each successful
attack counts as one application of the effect (meaning that an
attack that bestows 2 or more negative levels still counts as
only one application of the effect). For example, a wight gains
5 temporary hit points each time it bestows a negative level
with its slam attack. If it bestows another negative level while it
has 2 temporary hit points remaining from the first attack, the
new temporary hit points would replace the old ones.
Temporary hit points are “first-in, first-out.” Damage
should be taken off the oldest temporary-hit-point-granting
effect first; when that effect is exhausted, apply damage to the
next oldest effect. For this reason, you must track each supply
of temporary hit points separately.

[Lord Lorac Silvanos]

Wait, the Shambling Mound's Con bonuses don't stack? I swear I've seen several builds on the Wizards boards that make use of it stacking for massive HP. Was there something that I was missing there that isn't here?

The same effect from the same source almost never stack. In case of temporary effects this was made even clearer with the FAQ entry on temporary HPs.