Yes, because zephyr strike does not require the Attack action.
The Attack action is one type of action you can use in combat. There are other ways to make weapon attack rolls. For further explanation, see these related questions:
What does upper-case-A-Attack action vs. lower-case-a-attack mean?
What counts as an attack?
The cantrip green-flame blade is ...
Haste allows one additional Unarmed Strike
The reasoning is present in your own question; haste states that you can:
take the Attack (one weapon attack only)
And you point out that:
weapon attacks require the use of an actual weapon, while unarmed strikes are classified as melee weapon attacks.
Given that an unarmed strike is a melee weapon attack, ...
A dragon cannot use both multiattack and its breath weapon on the same turn
I've used the statblock from an Adult Black Dragon when answering this questions - as its available actions match your description. Not all dragons do have those exact options.
Like PCs, NPCs are generally limited to perfoming one action per turn (exceptions include a Fighter's ...
War Caster states:
When a hostile creature's movement provokes an opportunity attack from you, you can use your reaction to cast a spell at the creature, instead of making an opportunity attack.
When you use the action of such spells to deal damage, you are not casting the spell again1. Therefore, the War Caster text does not apply.
Note that this ...
It isn't exactly clear, but the implication is that you cannot delay when unconscious.
The section is titled Special Initiative Actions, and you cannot take "actions" while Dying
"You" must make the choice to delay, something your character is (probably) incapable of doing while unconscious
By choosing to delay... you decide to act... waiting to see what'...
The Fighter must wait until round 3
During round two in your scenario, when the Cleric heals the Fighter, the Fighter's turn has already ended for that round, so they would need to wait until the next round to take another turn.
The rules for death saving throws state the the saving throw is made at the start of the dying creature's turn (the Fighter, in ...
Yes, you can use a bonus action before readying an action
In the basic rules it states:
You choose when to take a bonus action during your turn, unless the bonus action's timing is specified, and anything that deprives you of your ability to take actions also prevents you from taking a bonus action.
So, unless the specific bonus action you are using ...
You can use bonus action to ready an action if you have a feature that explicitly allows you to take bonus action to ready an action.
The Bonus Actions section clarifies this.
Various class features, spells, and other abilities let you take an additional action on your turn called a bonus action. The Cunning Action feature, for example, ...
A bonus action can only be used for a specific ability that your PC has access to
A bonus action is specific to any abilities your class has access to. You cannot use your bonus action for anything other than abilities specifically marked as a bonus action in your ability/spell list, per the rules on bonus actions (emphasis mine):
Various class features, ...
The text in Cunning Action as written applies to both the turns a 17th level Rogue with Thief's Reflexes gets during the first round. If it said "once per round" rather than "on each of your turns", it would be unavailable on a Thief's second turn.
Donning or Doffing a shield requires an action
Donning or doffing armor is separate from the "Use an Object" action. Notably, a shield is the only kind of "armor" that takes 1 action to don or doff. The rules for donning and doffing are pretty clear:
Don. This is the time it takes to put on armor. You benefit from the armor's AC only if you take the full ...
You can almost definitely doff all shields
So, all item-use-actions are Use an Object unless expressly stated otherwise, since Use an Object gives itself that super broad mandate you've quoted in your description. The question, then, is whether taking a shield off is 'using' it. It seems like it should be, because in-fiction you're using the belt dohickeys ...
There is no interaction - you aren't using it, you are donning it.
Using an object covers:
You normally interact with an object while doing something else, such as when you draw a sword as part of an attack. When an object requires your action for its use, you take the Use an Object action. This action is also useful when you want to interact with more ...
You can use Fast Hands to equip a shield.
In the Player's Handbook, on page 193, the Use an Object action says:
When an object requires your action for its use, you take the Use an Object action.
A shield is an object, and donning or doffing a shield requires an action, so it seems to fall under Use an Object, just like any other object use that ...
The grapple has already ended automatically (no action needed)
Note that the description for the grappled condition includes:
The condition ends if the grappler is incapacitated
And being stunned causes one to become incapacitated:
A stunned creature is incapacitated (see the condition), can't move, and can speak only falteringly.
It is ambiguous
Crawford, though now unofficial, has stated:
The intent is that letting go of something requires no appreciable effort. But picking it up does...
We, in fact, do know exactly how much effort is required to pick something up as this is specifically called out under "Other Activity on Your Turn":
You can also interact with one object or ...
The question "Can you drop a weapon/item when it is not your turn?" is confusing primarily caused by the word "can" (including in the heat metal spell) so we have to address the portions separately.
1. You can be forced to drop an object not on your turn, such as by the Battle Master's disarming attack ability.
Disarming Attack When you hit a creature ...
This was harder to research and support than I'd first thought! I'd expect house rules to vary a lot on this one. I may be misunderstanding what's being asked, but I believe the answer to this is
RAW, you cannot choose to drop a weapon when it is not your turn.
Reason 1: You generally get to do things like this only on your turn.
The relevant section from ...
General Rules Apply
Unless overridden by a specific rule, which isn't the case except in combat (see bellow), the general rules apply. The section of the the rules on Monster's Actions reads:
When a monster takes its action, it can choose from the options in the Actions section of its stat block or use one of the Actions available to all creatures, such ...
No: A Homunculus may only take actions that are specifically described for it
There are two actions listed for the Homunculus' Statblock, which it is allowed to take:
Acidic Spittle. Ranged Weapon Attack: +4 to hit, range 30 ft., one target you can see. Hit: 1d6 + 2 acid damage.
Alchemical Salve (3/Day). The homunculus produces a salve and touches ...
It is important to note that underneath the Bonus Action section, it specifically states:
You can take only one bonus action on your turn, so you must choose which bonus action to use when you have more than one available.
In the situation in question, you are taking 2 Bonus Actions (even if one of them is being used by your Action and ...
Yes, and sort of
The description of the time stop spell says:
during which you can use actions
It says actions, multiple. A bonus action is an additional action:
Various class features, spells and other abilities let you take an additional action on your turn called a bonus action.
So the bonus action is an action and combined with your normal ...
RAW - Yes, a time stop user has both bonus action and reaction available
while you take 1d4 + 1 turns in a row
Emphasis mine. A turn is what let's a character do anything in a round of combat, and there's nothing in the wording of timestop to suggest that the turns you experience during time stop are unusual in any way, just that they happen one after ...