Starting combat with a reaction?

[5eNeedsDarksun]

I'm wondering what RAW is if someone attempts to start combat with a reaction. For example let's say my Assassin is sitting at the side of the road within an illusionary rock. His target walks by, enters his range, then leaves triggering an OA which he decides to use. Reasonable to allow this then roll initiative?

[Dualight]

At that point, it's an ambush, isn't it? Roll Initiative and apply surprise to the victim. Action/bonus action/ reaction distinction only matters during Initiative, when turns are in play.

[Keravath]

I'm wondering what RAW is if someone attempts to start combat with a reaction. For example let's say my Assassin is sitting at the side of the road within an illusionary rock. His target walks by, enters his range, then leaves triggering an OA which he decides to use. Reasonable to allow this then roll initiative?

RAW, it is entirely up to the DM to decide when the combat actually starts. He can decide this is when a character makes an attack or he could choose when a character intends to make an attack or any other circumstance if they like.

The process is:

Determine Surprise.
Establish positions.
Roll initiative.
Take turns.

The DM decides the point at which the "combat" starts which will be prior to any attacks being made but the point in time where this starts is entirely up to the DM. RAW, initiative does not start with the first person to say they are making an attack.

Personally, I would have rolled initiative before the op attack could be made. The assassin says that they might make an op attack and I back the scene up if necessary, roll initiative, and let the scene play out. The target can then walk by unaware on their initiative and the assassin can choose to take the opportunity attack or not - however the combat order is already decided.

----

On the other hand, resolving this is completely up to the DM, he could have everyone roll initiative when the assassin says they are going to attack - and start the combat at the point of declaration.

However, if the assassin says they are making an op attack and the target gets initiative, it may already have left the assassin's reach, since it was moving when the assassin declared the attack which can only be made when a target leaves your reach. If the target gets initiative, it might have left the assassin's reach before his weapon was ready, or the assassin blinked and missed their opportunity - due to not getting initiative. This depends on where the DM positions the creatures at the start of the combat.

The DM could also choose to start the target adjacent to the assassin rather than just having left his reach but in this case the target may not choose to keep walking and leave the assassin's reach. It depends on whether DM considers the assassin to have revealed themselves when they declare the attack or not (some do). If that is the case, there is nothing in the rules that requires the target to keep walking and thus give the assassin the op attack they planned to take.

Due to the difficulties, ambiguities and rulings involved in starting initiative on declaration of the op attack - I much prefer to start initiative before any of that happens - as a result, the assassin will only reveal themselves when they actually attack rather than when they say they are making an attack.

[ender241]

At that point, it's an ambush, isn't it? Roll Initiative and apply surprise to the victim. Action/bonus action/ reaction distinction only matters during Initiative, when turns are in play.

I agree with that approach. And it actually favors the player. They get a full turn (possibly two, if they win initiative) before the target gets to do anything.

[5eNeedsDarksun]

I agree with that approach. And it actually favors the player. They get a full turn (possibly two, if they win initiative) before the target gets to do anything.

So win or lose initiative, the Assassin in that case would still start combat with the reaction? If they lose the victim's 'action' is to walk by none the wiser, then start with the reaction OP. If they win it becomes a reaction attack regardless, whether it's a held action or an OA.

[Havrik]

I would say you can't ready an action until you are in combat initiative. So the ambush is just a regular attack.

Assassin is hiding with a rock. Victim walks by. Assassin says he intends to whack the victim as soon as he passes by.

Compare assassin's stealth check to victim's passive perception.

If assassin wins: Roll initiative. Victim is surprised and gets no action in the first round. Assassin can roll to hit with advantage because of being hidden.
If assassin fails: Roll initiative. Victim noticed assassin and is not surprised. If assassin wins initiative, he still gets to try to attack but without advantage because he was spotted. If assassin loses, the victim's reflexes were faster (i.e., he saw the assassin lifting the rock to strike, etc.)

This runs into the related scenario of "sucker punching" someone in the middle of a conversation. Some DMs just say "OK, roll to hit" but I generally think the victim should have a chance to see and react to the attack. So again I think this would be a "roll for initiative" scenario, and perhaps I would give the puncher advantage on initiative because it was so unexpected, but that's not RAW of course.

[ender241]

So win or lose initiative, the Assassin in that case would still start combat with the reaction? If they lose the victim's 'action' is to walk by none the wiser, then start with the reaction OP. If they win it becomes a reaction attack regardless, whether it's a held action or an OA.

Not a reaction either way. Havrik has it right. Even if the assassin loses initiative if the victim is surprised they cannot take any action on their turn, meaning the assassin can strike (with advantage, plus other assassin surprise goodies). If the assassin wins initiative they essentially get two turns before the victim can act, with the first one having the surprise/hidden attacker benefits.

[Corran]

So win or lose initiative, the Assassin in that case would still start combat with the reaction? If they lose the victim's 'action' is to walk by none the wiser, then start with the reaction OP. If they win it becomes a reaction attack regardless, whether it's a held action or an OA.
The victim passes by the hidden assassin. The assassin can choose to engage. If they do, initiative is rolled. During the first round the victim is surprised until the end of its first turn.

[Demonslayer666]

I would not have walking by someone provoke an opportunity attack outside of combat. You don't get your reaction until your turn starts in combat.

In that situation, I would have the assassin roll Initiative with advantage, and quite possibly have the person walking by at disadvantage.

[ender241]

I would not have walking by someone provoke an opportunity attack outside of combat. You don't get your reaction until your turn starts in combat.

In that situation, I would have the assassin roll Initiative with advantage, and quite possibly have the person walking by at disadvantage.

I don't think you need to introduce advantage/disadvantage into the initiative rolls. The surprise rules already account for the benefits so you wouldn't want to do both, and not using surprise takes away one of the Assassin's key abilities which was made for this very scenario.

[greenstone]

Some of these situations get a lot better if you stop thinking of "initiative is for when combat starts", and instead think "initiative is for when timing matters."

In other words, the combat rules aren't just for fighting, but for any sitation where it is important to know who gets to do something first.

For the OP's situation, this is an ambush. If the player has indicated that they are going to do something when the guard walks by, roll initiative, determine surprise, and start running the guard's patrol in rounds and turns.

[Chronos]

For the OP's situation, that's what the surprise rules are for. I have, though, seen situations where it does seem relevant: For instance, the party has just entered a room, but think they might be being followed. Several of the party then say things like "I ready an action to shoot anything else that comes through the door behind us".

[Unoriginal]

Is there any situation where a PC would prefer "attack with a Reaction" to "attack with an Action when opponent is denied their own action and reaction", if given the choice?

[Joe the Rat]

Some of these situations get a lot better if you stop thinking of "initiative is for when combat starts", and instead think "initiative is for when timing matters."

In other words, the combat rules aren't just for fighting, but for any sitation where it is important to know who gets to do something first.

For the OP's situation, this is an ambush. If the player has indicated that they are going to do something when the guard walks by, roll initiative, determine surprise, and start running the guard's patrol in rounds and turns.

I've used Charisma Initiative (which is basically just a Charisma check, though Alert does apply) when I've had to sort out the interactions in social situations, and have used it as a 'who reacts first' check when players are at odds with one another (i.e. who manages to grab the cursed crown and put it on first). Initiative is just damn useful when you have a table full of competing needs.

[Demonslayer666]

I don't think you need to introduce advantage/disadvantage into the initiative rolls. The surprise rules already account for the benefits so you wouldn't want to do both, and not using surprise takes away one of the Assassin's key abilities which was made for this very scenario.

Advantage and disadvantage is of course a DM's call. You are well within your purview to not use it in this situation if you don't want to, but you won't convince me otherwise without appropriate examples of when you would grant advantage or disadvantage on Initiative to show me your perspective of how you feel this is going too far. I think this is a perfect situation to warrant getting the drop on someone unsuspecting because you don't have to move from cover to make the attack. It would be far easier to beat them on initiative in this situation, as opposed to jumping out of a bail of hay, so they would have little chance of going first. They would likely react after the attack unless they had spidey sense.

It is clearly a surprise situation if the passerby is unaware of the attacker. And yes, I would use both surprise and advantage on Initiative for the assassin in this situation.

I'd also do something similar if the assassin were invisible, or dropping from above, the target was drunk, etc.

[ender241]

Advantage and disadvantage is of course a DM's call. You are well within your purview to not use it in this situation if you don't want to, but you won't convince me otherwise without appropriate examples of when you would grant advantage or disadvantage on Initiative to show me your perspective of how you feel this is going too far. I think this is a perfect situation to warrant getting the drop on someone unsuspecting because you don't have to move from cover to make the attack. It would be far easier to beat them on initiative in this situation, as opposed to jumping out of a bail of hay, so they would have little chance of going first. They would likely react after the attack unless they had spidey sense.

It is clearly a surprise situation if the passerby is unaware of the attacker. And yes, I would use both surprise and advantage on Initiative for the assassin in this situation.

I'd also do something similar if the assassin were invisible, or dropping from above, the target was drunk, etc.

That's fair. For me, it feels redundant to apply surprise, advantage, and disadvantage in this case.

For disadvantage, I feel like the person needs to have something making their reaction time slower than normal. Your example of a drunk person is perfect, actually. So if you successfully ambush a drunk person, I'd grant surprise and give them disadvantage. If they spot you or if you're not trying to hide, no surprise but they still would have disadvantage because they're drunk. Same thing if the target was asleep or perhaps very focused on something else.

For advantage, it's a little bit trickier because the surprise rules cover the scenarios where I feel like you would typically have advantage, if surprise wasn't a thing. Maybe you're right and this is the right scenario to apply both, because I can't think of a good example where I would. Maybe it's one of those "I'll know it when I see it" kind of things. Or maybe advantage on initiative is just not really a thing you can get outside of class features like the one the Twilight Cleric has. Might need to think about that one more.

[LibraryOgre]

Man, I prefer Hackmaster's initiative rules.

[strangebloke]

If you can ready actions out of combat, so can everyone else, and so there would need to be a mechanism to determine who goes first. The only time where you could get this kind of reaction off without the opponent doing the same thing would be in a case where the opponent doesn't expect to be attacked. AKA a hidden ambusher readying a reaction to shoot when their target gets within range.

...and this is where you realize you just literally reinvented a more wonky version of initiative and surprise from first principles.

If your player says this, just tell them to roll initiative.

[Kane0]

I'm wondering what RAW is if someone attempts to start combat with a reaction. For example let's say my Assassin is sitting at the side of the road within an illusionary rock. His target walks by, enters his range, then leaves triggering an OA which he decides to use. Reasonable to allow this then roll initiative?

I believe you can still take reactions before your first turn after initiative is rolled, as long as you aren't surprised?
Anyways, my rule of thumb is to always start with Initiative, then work from there.


Man, I prefer Hackmaster's initiative rules.
I'm not familiar, got a quick rundown?

[Mastikator]

RAW No.

Opportunity attack is a combat action.

Combat actions can not be used out of combat. https://twitter.com/jeremyecrawford/status/778650357824040961?lang=en

You can start a combat by declaring action to attack someone as they move away, this leads to initiative. If the attack is done from stealth then stealth vs perception is used to determine if the other target is surprised, if they are then they are surprised on their turn (which may or may not happen before yours, depending on initiative).

If you happen to win both initiative and stealth you get two turns of attacks.
If you fail both then the target sees your attack and is able to get in a turn before you.
(and so on)

[Darth Credence]

Is there any situation where a PC would prefer "attack with a Reaction" to "attack with an Action when opponent is denied their own action and reaction", if given the choice?

I think the idea is, they use a reaction to have an attack of opportunity, while still getting their normal turn when it comes up to get another full attack in. It's not attacking with a reaction or attacking with an action when opponent is surprised, it's and.

[Tanarii]

Determine surprise.
Roll initiative.
Act in initiative order.

No getting free attacks because you declared an attack. No reactions before combat begins.

[LibraryOgre]

Man, I prefer Hackmaster's initiative rules.


I'm not familiar, got a quick rundown?

Basically, Initiative determines surprise. The less likely you are to be surprised, the better your initiative die.

So, if you're setting up an ambush, and I'm walking along, not really combat-ready, you're going to roll a d4+modifiers, and I'm going to roll a d12+modifiers (there's numbers in between, and some abilities will raise or lower the die you use). Lower initiative is better, since combat is second-by-second.

If someone gets hit, their initiative becomes (second they were hit on) + 2, or their own roll, whichever is better. If a party has mixed surprise results, then earlier people can "raise the hue and cry" to lower everyone's initiative by 2 (including the enemy), and/or shake another person to lower their initiative to the mean of the two.

When you're surprised, your defense becomes a d8p (or d12p against ranged attacks, if you're moving), making it a lot more likely that someone with a d20p will hit you. You might also not have your shield or weapon ready. With Threshold of Pain and Trauma Saves, a first strike can knock out a couple of opponents, even if you don't kill them.

[Chronos]

What would be the benefit of lowering everyone's initiative by the same amount? Unless maybe there's a mechanic where a really good initiative lets you act multiple times before the enemy?

[LtPowers]

Some of these situations get a lot better if you stop thinking of "initiative is for when combat starts", and instead think "initiative is for when timing matters."

In other words, the combat rules aren't just for fighting, but for any sitation where it is important to know who gets to do something first.

For the OP's situation, this is an ambush. If the player has indicated that they are going to do something when the guard walks by, roll initiative, determine surprise, and start running the guard's patrol in rounds and turns.

There are two problems with this: Surprise applies only to the first round, and it prevents movement.

So the Assassin says "I'm going to ambush that guard when she walks by." They roll initiative. DM determines that the Assassin is hidden and the guard doesn't see him. The guard is surprised, and on the first round of initiative stops her patrol because she cannot use movement while surprised.

Okay, so the Assassin waits until Round 2 when the guard resumes her patrol, still unaware of his presence. But now the guard isn't surprised, so the Assassin doesn't get to score an automatic critical hit.


Powers &8^]

[Mastikator]

What would be the benefit of lowering everyone's initiative by the same amount? Unless maybe there's a mechanic where a really good initiative lets you act multiple times before the enemy?

Smaller dice means modifiers matter more.

[LibraryOgre]

What would be the benefit of lowering everyone's initiative by the same amount? Unless maybe there's a mechanic where a really good initiative lets you act multiple times before the enemy?

Depends on the situation, but this is a game where speed can be very important.

Since you don't have rounds, just seconds, shaving a few seconds off means there's fewer people surprised... if the bad guys went on 1, and will go again on 7 (slings have a speed of 6, if you're not taking careful aim), raising the hue and cry at 5 will help your allies who rolled 8 or 9 (dropping them to 6 and 7), meaning they're not surprised. It won't do anything to help your enemies, who have already gone past their initiative... once you hit that number, you're governed by Speed, not initiative.

I go into it in more detail here (https://rpgcrank.blogspot.com/2018/06/hackmaster-surprise-example.html), covering a conflict between 4 goblins and 4 adventurers. Hackmaster Basic is free (https://www.drivethrurpg.com/product/104757/HackMaster-Basic-free?affiliate_id=315505), and covers the same ideas (though there may be some details removed for the basic game; I haven't double-checked).

[Frogreaver]

Combat starts with initiative not with an attack or reaction attack.

One problem with transitioning from a more open ended game to a strict initiative structure is that some things can get wonky due to that transition. Best practice is to find out player intent and have initiative start before the moment they try to attack.

[Danielqueue1]

I think something that smooths a lot of these things out is allowing characters to be added to initiative and be surprised after initiative is rolled.

Target approaches, initiative is rolled.
Assassin succeeds on stealth check.
Target is unaware. Passes assassin.
Target is surprised, assassin attacks. Proceed with initiative as normal.

[Rukelnikov]

There are two problems with this: Surprise applies only to the first round, and it prevents movement.

So the Assassin says "I'm going to ambush that guard when she walks by." They roll initiative. DM determines that the Assassin is hidden and the guard doesn't see him. The guard is surprised, and on the first round of initiative stops her patrol because she cannot use movement while surprised.

Okay, so the Assassin waits until Round 2 when the guard resumes her patrol, still unaware of his presence. But now the guard isn't surprised, so the Assassin doesn't get to score an automatic critical hit.


Powers &8^]

Why would the guard stop walking if nothing caught her attention? Wouldn't she keep walking as if the assassin didn't exist?

[ender241]

Why would the guard stop walking if nothing caught her attention? Wouldn't she keep walking as if the assassin didn't exist?

Because that's how surprise works in 5e:


If you're surprised, you can't move or take an action on your first turn of the combat, and you can't take a reaction until that turn ends.

But the fact that you realize this doesn't make sense in this scenario proves LtPower's point, which I agree with: you shouldn't roll initiative until combat actually starts. Then there is a logical reason for a surprised creature to not act - they are caught off guard and trying to get their bearings and assess the situation.

[Rukelnikov]

Because that's how surprise works in 5e:

So since no one is doing anything in combat, why has combat started?


But the fact that you realize this doesn't make sense in this scenario proves LtPower's point, which I agree with: you shouldn't roll initiative until combat actually starts. Then there is a logical reason for a surprised creature to not act - they are caught off guard and trying to get their bearings and assess the situation.

Yeah, this is what I was going for

[ender241]

So since no one is doing anything in combat, why has combat started?

It shouldn't. LtPowers was addressing this:


Some of these situations get a lot better if you stop thinking of "initiative is for when combat starts", and instead think "initiative is for when timing matters."

In other words, the combat rules aren't just for fighting, but for any sitation where it is important to know who gets to do something first.

For the OP's situation, this is an ambush. If the player has indicated that they are going to do something when the guard walks by, roll initiative, determine surprise, and start running the guard's patrol in rounds and turns.

This seems to imply that initiative would be rolled even though there might be multiple turns before the guard actually reaches the assassin and fighting actually starts. Which doesn't seem right. Combat should start as soon as the assassin declares the attack, not sooner.

[Rukelnikov]

This seems to imply that initiative would be rolled even though there might be multiple turns before the guard actually reaches the assassin and fighting actually starts. Which doesn't seem right. Combat should start as soon as the assassin declares the attack, not sooner.

I agree.

"I blend in with the people of the street and backstab the guard when he passes near me"

If the guard doesn't pass near me, rolling ini was pointless, im still doing everyday stuff blending in, thus the guard has no reason to change what she's doing (unless she's a mind reader or something). This is still a Deception vs Insight check, and no initiative needed for that.

Assuming the guard hasn't sniffed something is going on, once she passes near you, roll ini, guard is surprised, player gets to decide if they are acting when the guard is right next to them, diagonally from them, 5 ft away, etc. because they are the ones changing the status quo of the scene.

[ender241]

I agree.

"I blend in with the people of the street and backstab the guard when he passes near me"

If the guard doesn't pass near me, rolling ini was pointless, im still doing everyday stuff blending in, thus the guard has no reason to change what she's doing (unless she's a mind reader or something). This is still a Deception vs Insight check, and no initiative needed for that.

Assuming the guard hasn't sniffed something is going on, once she passes near you, roll ini, guard is surprised, player gets to decide if they are acting when the guard is right next to them, diagonally from them 5 ft away, etc. because they are the ones changing the status quo of the scene.

Yep. Exactly.

[Zhorn]

Determine surprise.
Roll initiative.
Act in initiative order.

No getting free attacks because you declared an attack. No reactions before combat begins.
This is pretty much my reading of it, sounds more like OP is fishing for a freebie so that can get an attack before their turn AND also their surprise round turn, which as an assassin would be 2x advantage+crit sneak attacks against a surprised target.

[greenstone]

This seems to imply that initiative would be rolled even though there might be multiple turns before the guard actually reaches the assassin and fighting actually starts. Which doesn't seem right. Combat should start as soon as the assassin declares the attack, not sooner.

If there are multiple things the players want to do then yes, start initiative multiple turns before the guard gets there.

However, if the assassin player has said "I intend to attack the guard when they walk by", then initiative only needs to be rolled at the point the guard is close enough to react.

Then one of four things happens.

If the guard is surprised and the assassin beats their initiative then on the assassins turn, the assassin attacks and gets all the benefits of surprising their foe.

If the guard is surprised and beats the assassin's initiative then on the guard's turn, they do nothing, then on the assassins turn, the assassin attacks but has no benefits of surprise, and the guard can use a Reaction.

If the guard is not surprised and the assassin beats their initiative then on the assassins turn, the assassin attacks but again with no benefit to surprise.

If the guard is not surprised and beats the assassin's initiative then on the guard's turn, they do something. Maybe they stop, maybe they call for assistance, maybe something else. Something alerted them of danger (a faint noise, a smell, the hairs on the back of their next, something) so they will react accordingly.

[ender241]

If there are multiple things the players want to do then yes, start initiative multiple turns before the guard gets there.

Unless one of those things is to attack someone or something else that would prompt combat to begin (e.g. jumping out into the open, causing the guards to attack), then no, initiative shouldn't be rolled.

The rest of what you said was spot on though.

[Demonslayer666]

That's fair. For me, it feels redundant to apply surprise, advantage, and disadvantage in this case.

For disadvantage, I feel like the person needs to have something making their reaction time slower than normal. Your example of a drunk person is perfect, actually. So if you successfully ambush a drunk person, I'd grant surprise and give them disadvantage. If they spot you or if you're not trying to hide, no surprise but they still would have disadvantage because they're drunk. Same thing if the target was asleep or perhaps very focused on something else.

For advantage, it's a little bit trickier because the surprise rules cover the scenarios where I feel like you would typically have advantage, if surprise wasn't a thing. Maybe you're right and this is the right scenario to apply both, because I can't think of a good example where I would. Maybe it's one of those "I'll know it when I see it" kind of things. Or maybe advantage on initiative is just not really a thing you can get outside of class features like the one the Twilight Cleric has. Might need to think about that one more.

Perhaps advantage vs. disadvantage should just be an automatic success, but with initiative, you need a number to determine turn order.

I'm not going to pretend to know the math. :smallsmile: But it seems like applying both would be a significant difference to advantage vs. a normal roll.

[5eNeedsDarksun]

This is pretty much my reading of it, sounds more like OP is fishing for a freebie so that can get an attack before their turn AND also their surprise round turn, which as an assassin would be 2x advantage+crit sneak attacks against a surprised target.

...Or at least a 2nd sneak attack via the reaction in the opening round of combat.