Does a Firbolg lose their invisibility granted by hidden step if their summon makes attacks or deals damage?

Hidden step states:

As a bonus action, you can magically turn invisible until the start of your next turn or until you attack, make a damage roll, or force someone to make a saving throw. Once you use this trait, you can’t use it again until you finish a short or long rest.

My question is that if you summon a creature and command it to attack and deal damage for you, does that count as you making an attack/damage roll and therefore breaking your invisibility? Or does the fact that your summon is it’s own creature mean that you didn’t make any rolls that would break your invisibility (your summon did)?

How does moving silently with Greater Invisibility after taking an action work?

This question could be simplified with "How does moving silently away from enemy on same turn after casting Invisibility work", but I’ll present the full scenario in case it makes a difference:

A PC, who does not have special bonus actions, is under Greater Invisibility spell (or other equal effect) which allows actions without breaking invisiblity. At the start of their turn in combat, they are 10 ft (one empty 5 feet square between them on the grid) away from an enemy. They then move 5ft, uses their entire attack action to do a melee attack on the enemy (who does not go down). Then they tell the DM "I want to move back 5 feet, then use rest of my movement silently move away, so the enemy doesn’t know where I actually go."

What should DM respond, by the rules?

The PC can’t use hide action, or any action for that matter, because they already used their action to attack. Movement rules don’t have anything special about silent movement as far as I could find. But it also seems quite unreasonable and suspension-of-disbelief breaking to say "sorry, but you are utterly unable to move silently at this moment".

The reason the PC wants their location to not be known is to prevent the enemy from approaching to melee range and hitting them, in this case. The reason could also be the enemy using a spell like Moonbeam, or PC wanting the enemy to waste a blind ranged attack at PC’s (who could be in full cover now, even) last known location.

It’s of course easy to make a custom ruling here, involving some combination of PC Stealth, enemy Perception, and reduced movement rate, but I’m interested in what the rules say, including any language which supports handling this as part of a custom/improvised action, even though the PC doesn’t have an action to spare.

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??)