Do “Giant’s Stance” and “Improved Natural Attack” stack as a Medium character?

Giant’s Stance states the following:

While you are in this stance, you deal damage as if you were one size larger than normal, to a maximum of Large. This benefit improves your weapon and unarmed strike damage. It does not confer any of the other benefits or drawbacks of a change in size, such as a modifier to ability scores or AC, or an improved reach.

while Improved Natural Attack states the following:

The damage for one of the creature’s natural attack forms increases by one step, as if the creature’s size had increased by one category: 1d2, 1d3, 1d4, 1d6, 1d8, 2d6, 3d6, 4d6, 6d6, 8d6, 12d6. A weapon or attack that deals 1d10 points of damage increases as follows: 1d10, 2d8, 3d8, 4d8, 6d8, 8d8, 12d8.

Giant’s Stance does have an upper limit (Large), therefore, as a Medium creature, with Improved Natural Attack making the character already Large, Giant’s Stance would have no effect. However, my thinking is that Giant’s Stance would make the character Large and after that, Improved Natural Attack would be counted as one step higher; that is, Huge.

Is this correct or do both affect the base size (that is, both convert from Medium to Large) and are therefore redundant?

Enhancement bonuses to armour and natural armour stacking

The Ironskin spell states as follows (emphasis mine):

You gain a +4 enhancement bonus to your existing natural armor bonus (if you do not have a natural armor bonus, you are considered to have an effective natural armor bonus of +0). This enhancement bonus increases by 1 for every 4 caster levels above 4th, to a maximum of +7 at 15th level.

I have a Full Plate armour with a +5 enhancement bonus, and no dex bonus. At caster level 20, what would my AC be? Specifically, does the enhancement bonus to natural armour stack with the enhancement bonus of the full plate armour?

  1. 10 + 9 (plate) +5 (armour enhancement bonus) +7 (natural armour enhancement bonus) = 31 (with stacking)
  2. 10 + 9 (plate) + 7 (natural armour enhancement bonus) = 26 (without stacking)

Natural deduction with FindEquationalProof

Out of curiosity, I’m trying to implement a natural deduction prover in Mathematica using FindEquationalProof. So far, I’ve implemented a few of the easier rules:

axioms = {   ForAll[{A, B}, Implies[A && B, A]] (* conjunction elim. *),   ForAll[{A, B}, Implies[A && B, B]] (* conjunction elim. *),   ForAll[{A, B}, Implies[A, A || B]] (* disjunction intro. *),   ForAll[{A, B}, Implies[B, A || B]] (* disjunction intro. *),   ForAll[A, Implies[!! A, A]] (* negation elim. *) } 

Using these axioms, FindEquationalProof can solve some basic problems, like

FindEquationalProof[A && B, {axioms, B && A}] 

returns a 21-step proof. I can’t really say whether the axioms work correctly or not, and I have even less idea how to implement inference rules where cancellation is allowed (like in proof by contradiction). This would probably be easier with Resolve, but the point here is to “see” the proof, instead of just getting a confirmation that it’s True.

Is a critical failure on a natural 1 a rule or house rule?

There’s a question about this relating to 3.5e, but I couldn’t find one for 5e.

According to RAW, is a natural 1 a critical failure? And if so, under what scenarios does it apply, and what is the expected result?

One of my players is dissatisfied with my calls relating to 1’s* but I don’t have my books handy and I’m having trouble figuring out if the whole shebang is a very popular houserule or actually in RAW.

*I have a feeling that I am likely in the wrong here and it’s more of a same-page issue than a mechanics one, but I want to check what the book’s ruling is before we sit down to have a conversation about it. Our table dynamics aren’t the question here; I just need to know the mechanics to make an informed decision.

Do Storm Giants have a Natural Armour value?

A Storm Giant’s AC is 16 due it its scale mail, and it has a Dex modifier of +2, so without the scale armour the giant’s AC would be 12. However, a Cloud Giant has a Natural Armour of 14 and a Dex modifier of +0, meaning its AC calculation is [10+0+Y], where +Y is its natural armour bonus (thick/magical skin), in this case +4.

Does this mean the more powerful Storm Giant does not have this natural armor bonus? If its scale mail is taken away, would its AC be 12, 16, or something in between?

Hill Giants have a Dex modifier of -1 and a Natural Armour of 13, indicating their natural armour bonus (+Y) is also +4.

Can a Paladin use Divine Smite when attacking (with a natural 20) a creature immune to the weapon’s damage type?

Prompted by this question about Sneak Attack and Immunities, it seems a character can hit (although for 0 damage) with a weapon which deals damage to which the target is immune.

What would be the result if a Paladin rolled a 20 (with a non-magical slashing weapon), attacking a creature immune to non-magical slashing damage, if the Paladin casts Divine Smite?

Note: I specify a natural 20 in the actual question to avoid discussion about armor class when considering the result.

optimize user interactions to solve ambiguity in natural language questions

am doing research about how to reduce user interactions with the system to solve ambiguities in natural language questions to retrieve data from databases. note: those systems for technical users to enable them to restore data from databases without knowing query languages. Anyone have a suggestion for reducing those interactions.

Is there a *natural* problem that is NP-hard on trees, but in P on non-trees?

It seems intuitive that any natural problem that is NP-hard on trees, should be hard on graphs that are not trees. But perhaps this is wrong?

Question: Is there some natural decision problem on graphs that is NP-hard when we are promised the graph is a tree, but in $ P$ when the graph is promised to not be a tree.

Thoughts:

  • Here’s a list of problems that are NP-hard on trees: https://cstheory.stackexchange.com/questions/1215/np-hard-problems-on-trees The ones I saw were all also hard on non-trees.

  • Given any NP-complete language $ M$ that is NP-complete on trees, you can obtain a tautological example via the decision problem $ L$ where $ x \in L$ iff $ x \in M$ and $ x$ is a tree. This is pretty unnatural though.

  • Is there some object that trees have a lot of of, but non-trees only have a few of?