How does Crown of Stars interact with Greater Invisibility?

Suppose I already have the spell Greater Invisibility cast on me, and then I cast Crown of Stars.

From the description of Crown of Stars:

Seven star-like motes of light appear and orbit your head until the spell ends.

My questions are: Are the motes invisible?

Supposing the motes are visible, do I still get the benefits of Greater Invisibility?

Again, supposing the motes are visible, "real-world" logic would tell me that if someone were to try to attack me, the difficulty of trying to hit an invisible person would be somewhat mitigated by the fact that I could just aim at the motes. Similar logic seems reasonable for someone targeting me with a spell.

However, (my reading of) the in-game mechanics would tell me that I am still under the invisible condition (as nothing has ended Greater Invisibility) and thus I should still get all the benefits.

Does a bonus action end invisibility gained from the Boon of the Night Spirit?

As the title says really. The Boon of the Night Spirit says:

While completely in an area of dim light or darkness, you can become invisible as an action. You remain invisible until you take an action or a reaction. (DMG, Chapter 7, page 232)

If a character did something that they can do as a bonus action (certain spells, dash or disengage for a rogue, etc.), would the invisibility end?

Invisibility NOT doing more than exactly what the spells says it does

Please help settle this long running dispute regarding how the invisibility spell works. Invisibility when cast on an object makes the object vanish from sight.

https://www.d20srd.org/srd/spells/invisibility.htm

However a fellow players seems insistent on claiming this also provides an additional property not detailed in the spell description. Namely, for example, if the spell is cast on a closed door. the door vanishes from sight revealing the room or area beyond.

My counter to this is to point to the fact invisibility is of the illusion school and the property he is assuming the invisibility spell additionally possesses belongs fundamentally in the divination school.

A ring of X Ray vision for example relies on the spell True Seeing which is of the divination school. Similarly Clairaudience/Clairvoyance, a spell by its effect that would more adequately reflect the ability to see in to an area that is blocked to line of sight is also of the divination (scrying) school.

Is there a general rule regarding exceptions I can point to, that states along the lines of if an exception isn’t documented then it isn’t a principle of the game rule?

I think his problem is that he’s seen invisibility depicted in certain popular media such as sci-fi and fantasy films and assumed that the D&D invisibility spell must work like that by reference and inference.

Does the duration of the invisibility from the Firbolg’s Hidden Step trait allow me to make an attack roll with advantage on the following turn?

The firbolg’s Hidden Step trait (VGtM, p. 107) is described as being active "until the start of your next turn" at most:

As a bonus action, you can magically turn invisible until the start of your next turn

I’m unclear on the exact mechanics of turn starts. For instance, if I use Hidden Step as a bonus action at the end of my turn, would the invisibility stay active for my next attack?

My initial reading was "no" as the trait would stay active from when I use it, into the next round, and drop as soon as my turn came up in the initiative order. I would then become visible, and take my action. This also gels conceptually: I can use Hidden Step to protect myself from combat for a round, or I can use it to gain advantage on an attack. But I can’t use it for both.

However, I’ve also read that advantage for invisibility is determined at the start of the round, and thus the advantage would in fact carry over to the next round’s attack, as if I was attacking from hiding or something similar.

Which is it, and what source would resolve it?

Can “Shield of Faith” counter invisibility?

The wording of Shield of Faith suggests that it can be used to reveal a known but invisible enemy:

A shimmering field appears and surrounds a creature of your choice within range (60 feet), granting it a +2 bonus to AC for the duration.

Unlike many spells, there’s no requirement for the caster to see the target.

A Jeremy Crawford citation indicates that there needs to be a clear path from the caster to the target.

A fairly common "boss fight" scenario is that the heroes enter the boss’ lair, the boss delivers an ominous speech, everyone rolls initiative, and on the boss’ first move they cast Invisibility (or Greater Invisibility). Would casting "Shield of Faith" on the boss be a cheap counter? (The boss getting an AC boost, of course, is just hilarious).

How does invisibility work in combat?

In one fight I want 2 duergar and one kobold to fight my party. I want the party to see them all and then let the duergar become invisible. Once they are, do they need to roll stealth to sneak up on the party and does the party than roll perception in order to search for them? Or can I just go with the duergar up to one ranger and attack him (with surprise??)

Does grapple end the Invisibility spell for the grappler?

I was looking through the Sage Advice Compendium when I noticed this:

When you make a Strength (Athletics) check to grapple or shove someone, are you making an attack roll?

Again, the answer is no. That check is an ability check, so game effects tied to attack rolls don’t apply to it. Going back to an earlier question, the hex spell could be used to diminish a grappler’s effectiveness. And if the grappler’s target is under the effect of the Dodge action, that action doesn’t inhibit the grapple, since Dodge doesn’t affect ability checks.

I had always played that the 2nd-level invisibility spell would end on a grapple, since it counts as an attack, but this seemed to suggest otherwise.

I researched this a bit and found a tweet by Jeremy Crawford from December 2015, which seemed to suggest that it was indeed an attack roll:

Grappling/shoving an enemy does end the sanctuary spell on you, since you have made an attack.

My best guess is that you must take the Attack action to perform an ability check, as grappling in the PHB is called a “special melee attack” (PHB p. 195), although that doesn’t make a huge amount of sense:

[…] you can use the Attack action to make a special melee attack, a grapple. […]

Do these two answers by Crawford contradict each other? And should the invisibility spell end when a grapple is attempted?

The description for the invisibility spell says:

A creature you touch becomes invisible until the spell ends. Anything the target is wearing or carrying is invisible as long as it is on the target’s person. The spell ends for a target that attacks or casts a spell.