Arial Black
Adventurer
Just a point of clarity, you take your attacks later in your turn, not later in the round.
I stand corrected. I mis-typed.

Just a point of clarity, you take your attacks later in your turn, not later in the round.
The rules say "You choose when to take a bonus action during your turn, unless the bonus action’s timing is specified..." which suggests that, absent other provisions, you can take your bonus action any time you please. There is no express provision allowing you to use a bonus action during your movement, but I don't see anyone suggesting that you can only break up your movement with your extra attacks....
If you were correct and you could drop a bonus action into the middle of an Attack Action, why wouldn't they have called this out, the way they called out movement? I mean, the movement rules are pretty clear - it's called out in a completely separate paragraph that if you have multiple attacks, you can move between attacks.
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I look at it slightly differently. While the resolution is handled sequentially, the effect isn't. From a design perspective, you have a choice- either tell the player to declare everything first and then resolve, or allow the player to resolve the action sequentially.
5e has gone with the player empowerment route of allowing the player to resolve sequentially. It makes for less "wasted" action as in, "I magic missile target A twice and B once. Oh, the first one killed Target A? Guess that second missile was pointless."
Sorry, I assumed that's why he was talking about when the Attack action ended, as that's clearly important for the Shield Master shove (and not much else AFAIK).
[MENTION=6799649]Arial Black[/MENTION] - I agree, that the rules delineate what you can do.
However, nothing in the rules says that you can divide up an Attack Action with anything other than movement, and then only if you have multiple attacks. If you have a single attack, obviously you cannot divide up the Attack Action at all.
The only exception seems to be when you gain multiple attacks and you want to move.
If you were correct and you could drop a bonus action into the middle of an Attack Action, why wouldn't they have called this out, the way they called out movement? I mean, the movement rules are pretty clear - it's called out in a completely separate paragraph that if you have multiple attacks, you can move between attacks.
If the intent was to allow bonus actions the same latitude, wouldn't it be called out the same way?
Since it isn't called out and in fact the only thing about timing that is called out is that you can do it during your turn or at the time specified by the bonus action, why would you presume that you could bonus action during an attack action?
In every role playing game, whether on the tabletop or a video game, there is a conflict between the rule system and the fiction it is modeling. To create a rule system that was a realistic simulation wouldn't just be difficult, it would be a waste of time--no one wants that kind of granularity--but a complete abstraction is very unsatisfying. The happy medium is somewhere in the realm of having the player free to state what his character will do in a scenario, and for the most part how the character will do it, and then use the rule system to abstract that into something that can be resolved with a die roll.
Obviously, your game rules must have a lot of constraints built into them. Constraints are necessary for a number of reasons, including making sure everyone gets a turn and that the game flows along, and also so that your character has limitations that can be overcome as it gains power. In broad terms, then, when your character can't do something the limit should be either in service to the gameplay or to the fiction. Arbitrary limitations and restrictions on what your character can do in the game are a disservice to both causes, mucking up the gameplay while you figure it out and bringing your awareness back to the books and character sheets instead of the monsters and magic your character is dealing with. There's not much you can do about it when your RPG is a video game, you just deal with the arbitrary limitations and watch your cooldown timer. It is what it is. When you're playing on a tabletop (physical or virtual) with a live Dungeon Master, though, everything changes. The player is liberated to come up with the zaniest free-form swing-from-the-chandelier Jackie Chan sequence he can imagine, and the Dungeon Master will parse it into one or more rolls of the dice and tell him how it turned out.
So, when you maintain that an action in combat must be resolved in accordance with strict timing requirements which are implied rather than expressly enumerated, and that a character's turn should be resolved according to rigid procedure such that an action must be completed in its entirety before you can consider a bonus action it enables, I disagree. There is no difference between the shove you get as a bonus action and a shove you can make as part of the Attack Action, and making a timing distinction serves neither the gameplay nor the fantasy. Only if you adhere to an inflexible, procedural, meta-gamist approach to a character's turn in combat will you gain any benefit from using Jeremy's new restrictive approach to timing, and I do not.
To put it another way, the Dungeon Master can interpret the Shield Master feat in a couple of different ways. The first, which I'll call the Hriston approach, emphasises role-play by giving the DM the flexibility to adjudicate the entire sequence of a character's turn as a whole. The second, which I'll call the Crawford approach, emphasizes most emphatically roll-playing by demanding an iterative procedural resolution of the turn without regard for fantasy verisimilitude. Your position doesn't sway me because you favor the roll-play of the Crawford approach, while I strongly prefer the role-play of the Hriston approach. I will, almost every time, choose role-play over roll-play.
You know he's not confused, you're just being snide. His point, which is valid in my opinion, is that being a DM ideally involves taking what a player wants his character to do and resolving it using the rules, not setting out arbitrary limitations and conjuring extra timing constraints. If a shield master character shoves first, then takes all the attacks granted by an attack action, then both the attack action and the bonus action from Shield Master were used. If one or more of those attacks is frustrated before it is taken, then it was just the attack action. Hriston's point, if I may speak for him, seems to be that as a human being running a tabletop RPG (and not as a computer,) we are perfectly capable of looking at the character's entire turn instead of constraining ourselves to consider each action, attack, flourish, or 5 feet of movement individually, in isolation, with rigid attention to what must come first.
I think one of the clearest indications that this new and revised Shield Master comment from Jeremy Crawford is bad advice is that across the dozens of pages of this thread, it seems that most of the people who defend his new interpretation of the rule do so only in theory, while 'confessing' that they would not adhere to it in their own game. Whether 'allowing' the shove to come between attacks, or whenever the character wants, or declaring by house rule that the attack action itself is unnecessary, there don't seem to be a lot of commenters who are eager to use Jeremy's new Shield Master advice in their own game. And why would they? At no point during the years when Jeremy's advice (whether because he was drunk in line at the grocer's or not) was to "take your bonus shove whenever you want it" did the Shield Master feat dominate the game. I think most of us need a much better reason to tell a player he can't string his attacks together the way he wants to on his turn than "Well, see, Jeremy changed his mind, so... sorry."
Ultimately, the rules are best when they are at their most flexible. There is no way for a set of rules to contemplate every situation in every game, and the magic of tabletop RPGs is that they don't have to. The DM can apply the rules to resolve the acts and efforts of the player characters without having to look at the Actions in Combat section like an instruction manual from Ikea.
If, at the end of a shield master's turn, the Attack Action has been taken and a bonus action shove was taken, the conditional described in the feat has been satisfied regardless of the sequence of attacks. The ability to reconcile complex behavior during a combat turn into movement, action, bonus action, and flourish is part of what makes a live D&D game better than playing Baldur's Gate on your PC.
No general rule allows you to insert a bonus action between attacks in a single action. You can interrupt a multiple-attack action with a bonus action/reaction only if the trigger of the bonus action/reaction is an attack, rather than the action.
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 basically you don't actually care how the rules actually say to resolve something. Basically you ignore all requirements on abilities that you think are arbitrary restrictions that you think don't go with the fiction being modeled. I get it now. I want to say 1 thing and then you can have the last word as I don't think continuing a rules conversation with someone that holds those beliefs is going to be productive.
1. Consider how the shield shove attack followed by an attack is modeled in the featless game. To me everything you want about the fiction is already present in a game without feats and by virtue also in a game with feats. All shield master does is give a mechanical benefit in a particular situation. Everything else involving shield shoving can already be modeled by the other rules of the game. Are you sure the issue isn't just that none of those other models allow you to get a sweet mechanical benefit when performing the shield shove then attack sequence? Because even a level 1 fighter is capable of shield shoving then attacking (he just has to do it over 2 rounds).
This is the 'argument from ignorance' fallacy. Here you are asserting, without support, that there are ONLY two options, just because you don't know of other options. There is at least one more option, and there may be more:-
3) Play the Rules As Written. What JEC says or means is irrelevant to RAW.