When and how does combat start in a standoff?

Question

I run Adventurers league at a local game cafe with a veteran group that has lots of experience playing prior editions. However these players knowledge of the rules is an amalgamation of 5e rules and previous editions' rules, so we're never quite sure if a specific rule belongs to 5e or not.

The question I have is in the following scenario, when exactly does combat start? Are 'readied actions' valid in this scenario and how do they interact with the 5e initiative rules?

I acted under the assumption that combat starts when the first creature decides to take a hostile action, rather than just threatening to do so--however this may have been too late.

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The PCs were involved in a standoff with a group of bandits. Both sides came upon each other unaware. We didn't roll initiative since although everyone was on edge, no one wanted to initiate the fight. Perhaps we should have rolled here but I know these players take 'roll initiative' as 'roleplay is done just kill everyone' and I wanted to build some tension first.

Most of the players told me they'd shoot if the enemies made any sudden moves. After a couple minutes of heated negotiation I decided combat began when one of the bandits got jumpy and was about to shoot on instinct. I decided the jumpy bandit didn't surprise anyone, and since positions were already determined on a grid, I called for an initiative roll. I decided that the bandit with the highest initiative was my 'jumpy' bandit. When none of the PCs beat his initiative his turn started and he shot one of them.

At this point a few players shouted they had readied actions to shoot the first person who acts, so they should get to shoot now (before the bandit, using their reactions) and take their turns later in the round.

I honestly didn't know how to respond to this for a moment, but then I just said "It's a standoff, everyone's ready to shoot the first person who moves. That's why we're rolling initiative--to see who reacts fastest".

Answer 1

You were right!

In that type of situation, everyone is ready to begin fighting at any moment. Everyone basically is 'readying' for their fight - not just the PCs.

Readied Actions

These actions do require a trigger to be specifically stated, as well as the action they will take if triggered. In a general situation, most Readied Actions take place during combat when the turn structure is in place. However, it may be possible to ready an action outside of combat, but you as the DM will need to adjudicate the possibility of that.

From the Players Handbook, page 193 (emphasis mine)

...you can take the Ready action on your turn so that you can act later in the round using your reaction.

First, you decide what perceivable circumstance will trigger your reaction. Then you choose the action you will take in response to that trigger, or you choose to move up to your speed in response to it...When the tirgger occurs, you can either take your reaction right after the trigger finishes or ignore the trigger.

Your situation

In order for the players in your situation to their ready action, they would need to have explicitly stated what their trigger was and what the use of their reaction would be. However, given that the combatants were also likely 'readying actions', the initiative roll works because everyone is on even ground.

Even if this was a one-sided readied action event (where the combatants whom the PCs were fighting were not prepared for a fight), the trigger for the PCs readied action is the attack - which needs to be completed before they can act.

In addition, a readied action is just that, something that is being held waiting for the trigger. That could be a caster having started their spell and waiting for the event to finish casting it (if no event, the spell slot is still lost), or the bowman with their arrow nocked and bowstring pulled and ready to fire, etc. etc. That sort of action may also move towards a specific resolution (FIGHT!) rather than hoping for an alternate resolution (NEGOTIATE!)

The developers have your back

Jeremy Crawford Tweeted about when Readied Actions are available.

The options, including Ready, in the "Actions in Combat" section (PH, 192–93) are meant to be used in combat, after rolling initiative.

but he also suggested an alternative:

Your readiness can guard against being surprised. Otherwise, you roll initiative as normal. The DM might give advantage

Jeremy also had a nice discussion on this podcast about readied action and initiative (starts at about 6:10).

Unspecified Initiative Rolling

There is a potential issue in how you roll initiative that should be mentioned. This section is not a judgement against the actions described, but merely a reminder to have a consistent and agreed upon method of initiative at your table.

If you are trying to create a level playing field, then you should roll specifically and openly for each combatant. While the DM does have "control" to make changes behind the scenes, what you have done is to allow the situation to play out as you wanted it to rather than be dictated by the rolls of the dice.

Even though you had one guy ready to go, you could have created a narrative around why the other mook got to go first - and that would have been a more consistent and fair way to adjudicate your initiative rolls.

The decision to assign the highest roll to the guy who was about to shoot may have further incensed the players and made them feel they didn't get the opportunity they should have. It doesn't mean what you did was wrong, but it may have contributed the feelings at the table. It may not have, but I think it's something you should be aware of and consider when rolling your initiative.

Answer 2

You were correct

The Ready action is an "Action in Combat" and until the initiative is rolled you are not "in combat".

To stop the cognitive dissonance, rather than saying "One of the bandits fires! Roll initiative" say "One of the bandits is about to fire! Roll initiative". This makes the narrative better match the mechanics.

One other thing to consider is giving everyone advantage on the initiative check since they were all hyper-keyed up. You might think that if everyone has advantage then it makes no difference but that is not correct. Because the probability curve for advantage is non-linear, the effect on the flat bonus difference is amplified - a person with +3 vs +0 will win 59.5% over the time without advantage on either roll but 61.75% with advantage to both rolls (see anydice). In general, players will have better bonuses than their enemies so this usually helps them.

Answer 3

You were right about the rules, but wrong in how you handled it.

If a player says they ready an action before you've rolled initiative, you need to immediately call for initiative since readying must happen in initiative order. You can't simply nod OK to them, then later state that readied actions don't work that way. You've just built all this tension and then retroactively changed the conditions as they understood them. I would have thrown a fit as a player :)

This answer is from Pathfinder, but it's essentially the same problem; that is,

the key point is you need to have initiative before anyone can act to delineate order

The rules don't come out and say exactly when combat starts, but a good rule of thumb is

you need initiative as soon as order of events matters

Whether or not the event is an actual attack.