How does multiple creatures sharing a turn interact with once-per-turn abilities?

This question was brought to mind upon reading one of the bullet points in this answer (regarding a Marilith’s ability to take a reaction every turn), which reads:

  • This limits you to one attack per group for certain implementations of group initiative, as well as for groups of summoned monsters that share a turn

This is noticeable in many of the "Conjure …" spells which share this common line (emphasis mine):

The summoned creatures are friendly to you and your companions. Roll initiative for the summoned creatures as a group, which has its own turns.

The language reads "a group…has its own turns", not "the summoned creatures…have their own turns", which lends to the idea that the summoned creatures are not just sharing an initiative, but actually sharing the turn. This Q&A brings up other cases as well, so it does not seem out of the ordinary that multiple creatures could share a turn. My question is: how does that interact with once-per-turn abilities such as the Marilith in the question referenced above, the Cavalier Fighter’s Vigilant Defender, or monsters’ legendary actions.

How does supernatural light interact with magical darkness, and vice versa?

Let’s say a character has the exalted feat Nimbus of Light which makes him shed light:

Your radiance sheds light as a common lamp: bright light to a radius of 5 feet and shadowy illumination to 10 feet. You can extinguish this radiance at will and reactivate it again as a free action.

What would happen if he enters the area of a Darkness spell?

Normal lights (torches, candles, lanterns, and so forth) are incapable of brightening the area, as are light spells of lower level. Higher level light spells are not affected by darkness.

Since the light is supernatural (all exalted feats are supernatural) it doesn’t qualify as "normal", it could qualify as a spell, but supernatural abilities don’t have "levels", and often, as in this case, they don’t emulate the effect of a spell like most spell-like abilities do.

So, what would be the proper way to resolve this situation?

  1. Should the DM assign a virtual level to the supernatural ability by comparing it to similar spells?
  2. Since supernatural abilities can’t be dispelled and are not subject to spell resistance would it be reasonable to assume supernatural light behaves like "normal" non-magical light, and it doesn’t shine inside magical darkness?
  3. Does any supernatural light trump over all kinds of magical darkness?

How does the Dimensional Loop’s Fold Space ability interact with areas of effect?

The magic item Dimensional Loop (Acquisitions Incorporated, pg. 220) has an ability called Fold Space which says:

Choose a space you can see within 60 feet of you (no action required). You treat that space as if it were within 5 feet of you until the end of your turn. This allows you to move immediately to that space without provoking opportunity attacks, or to interact with objects or creatures in that space as though they were next to you (including allowing you to make melee attacks into that space).

Suppose Jim Darkmagic is having a dual with another mage, and they are 50 feet apart. The mage uses its action to hold a fireball spell until he sees Jim casting a spell. On Jim’s turn, he uses the Fold Space ability of his Dimensional Loop and chooses the space the mage is occupying. Until the end of Jim’s turn, the mage’s space is treated as if it were within 5 feet of Jim. Next Jim starts casting inflict wounds on the mage. Seeing this, the mage uses his reaction to cast fireball centered directly on Jim.

Is the mage considered to be within the area of effect of his own fireball?

Similarly, does Jim need to be wary of casting his own fireball on the mage until next turn?

How does Mythic Haste interact with 1 round spells?

Mythic Haste states:

Affected creatures gain an additional move action each round.

The rules for casting spells state:

A spell that takes 1 round to cast is a full-round action. It comes into effect just before the beginning of your turn in the round after you began casting the spell. You then act normally after the spell is completed.

If I cast a 1 round spell before using my move action, does the spell finish early?

How does resistance/vulnerability/immunity interact with carryover damage after reducing a Polymorphed (or Wild Shaped) form to 0 HP?

A caster casts polymorph on another creature. Let’s say the polymorphed creature has 10 HP in its new form, but takes 30 piercing damage and its current form is reduced to 0 HP. This causes it to revert back to its original form, with 20 more piercing damage that would carry over. However, its original form is resistant to piercing damage.

How much damage would the new form actually take? Would its original form’s resistance to the damage type apply to the carryover damage?

The same question can be extended to the original form having immunity or vulnerability, as the answer would ostensibly use the same logic.

The druid’s Wild Shape ability also works similarly to polymorph in this regard (if you reduce the new form to 0 HP, then any remaining damage carries over to its original form), so I suspect the answer would be similar for a similar question about Wild Shape.

How does flexible casting interact with itself?

As I find builds about the Coffeelock (for peoples who doesn’t know, it’s a build that hollow you to have an infinite amount of 5th level spells slot RAW, involving a sorcerer multiclassing in warlock), I turned out asking myself a question:

How does flexible casting interact with itself?

To be clear, I want to know if you can turn created spell slots into sorcery points RAW (which could mean you have an infinite source of sorcery points if you need to do metamagic with your infinites spells).

How do the physical traits granted by the draconic sorcerer bloodline interact with a changeling’s shapechanger trait?

Sorcerers with the draconic bloodline develop a thin sheen of dragon-like scales and can eventually manifest wings. How does this interact with the changeling’s ability to alter their shape?

For instance:

  • Can they maintain the armor bonus of draconic resilience when they are mimicking a race without scales?
  • Can they manifest wings and then change them to match an Aarakocra or Winged Tiefling while still maintaining their original flight speed?

How does the address bus , Memory Controller , RAM and CPU interact?

So I was taking a course and didnt quite get what was happening so I tried to research the material and found 2 different representations for the topic.

2 Photos

CPU getting data/instructions from RAM

So the first one shows that the Memory controller is part of the CPU and the process of sending data is:

CPU -> Memory controller -> Address bus -> RAM -> Data Bus -> CPU

The second shows :

CPU -> Address Bus -> Memory Controller -> Ram -> Memory Controller -> Data bus -> CPU

I did search for the topic but couldn’t find an answer as most people don’t show memory controller and address bus interaction

So does anybody know which is the right one ?

Thanks in advance

how do a changlings change apearance and a druids wild shape interact?

A changelings change apearance states

You also can’t appear as a creature of a different size than you, and your basic shape stays the same; if you’re bipedal, you can’t use this trait to become quadrupedal, for instance.

But seeing that with a druids wild shape can change you into a creature that is quadrupedal and a differernt size as yourself, does this mean that after that you can change into another quadrupedal creature of that same size?

lets say you are a normal 2 legged walking medium changeling and you wild shape into a 4 legged walking large saber-toothed tiger. does that mean that you can use the change apearance feature of the changeling to change into another 4 legged walking large creature like a dire wolf? and can you use this feature to change apearance into a creature outside of the possible druid wild shapes? for example a creature with a higher CR?

How does the Earthquake spell interact with total cover?

The rules on “Area of Effect” state (emphasis mine):

[…] A spell’s effect expands in straight lines from the point of origin. If no unblocked straight line extends from the point of origin to a location within the area of effect, that location isn’t included in the spell’s area. To block one of these imaginary lines, an obstruction must provide total cover.

So for most spells, if somebody is on the other side of a wall they cannot be target by an area of effect spell whose point of origin is on the directly opposite side of the wall. I’m unsure if this is the case with the earthquake spell in particular which states:

[…] For the duration, an intense tremor rips through the ground in a 100-foot-radius circle centered on that point […]

[…] each creature on the ground in the area must make a Dexterity saving throw. […]

[…] The tremor deals 50 bludgeoning damage to any structure in contact with the ground in the area […]

This spell makes an area of effect centered on a point but is a bit unusual in that it can target structures as well as creatures. Can earthquake affect something on the directly opposite side of a wall from its point of origin?