D&D 5E Surprise and Sneak Attack

[Flamestrike]

And, until the Assassin commits to something that will start combat, combat doesn't start.

He has committed to an action. Watch:

DM: Your Assassin sneaks up to the Guard through the shadows. He looks unaware of your presence, gazing intently at a copy of the famous magazine 'Sexy Orc Maidens of Waterdeep'. You're 30' away from him.
Player: I take careful aim with my Crossbow and shoot him in the spine.
DM: Are you SURE you want to shoot him?
Player: Yes!
DM: You bring your bow to bear, and the twang of the bow string echoes out through the dim night. Roll initiative.

Scenario 1) The Guard goes first, he's surprised (cant move or act on his turn). He then stops being surprised and the Assassin makes his attack roll (no critical hit).
Scenario 2) The Assassin goes first, the Guard is surprised (critical hit)

 

[Flamestrike]

The same is true when you say "I stab the elf". That is your declared action. Someone could beat your dex check and kill you before you do it, but you are going to stab the elf.

As highlighted above, that's down to a question of narration, not an issue with the rules.

Thokk: 'I stab the Elf'
DM: (narrating) 'As you're all taking about what to have for dinner, Thokk screams in rage, his hand reaching for his sword, and murder in his eyes... directed at the Elf! Roll initiative!'

 

[billd91]

In this approach, surprise would not depend on "Initiative was just rolled"--it would be the result of "On my last turn, I was not aware that combat was imminent, and since then combat has begun." If the action that starts combat is an assassin attacking an unaware target, the assassin gets the benefit of surprise, end of story. If the assassin sees the result of the initiative roll and for some reason decides not to attack, okay. You don't attack. Nothing happens. If the initiative roll doesn't change anything, it doesn't matter if it's followed by combat or not.

I can't really go for that and I don't think it's particularly square with either the rules or fairness within the construct of the game. It leaves out the potential for a character to try to get the drop on the opposition but fail because the opposition turned out to be faster or more aware than the combat initiator thought. I wouldn't necessarily require an assassin trying to surprise his target to follow through on the attack, but the whole thing that initiated rolling initiative was a hostile move - think of it as a gun hand twitching toward a holster or a hand going to the hilt of a weapon. Once that's in motion, initiative will be rolled and then we'll see who manages to react first.

 

[Flamestrike]

If the action that starts combat is an assassin attacking an unaware target, the assassin gets the benefit of surprise, end of story. If the assassin sees the result of the initiative roll and for some reason decides not to attack, okay.

How is the Assassin seeing the result of the Dexterity check he just made?

He's aware he's in a game is he? He can see the results of dice rolls his player has just made to resolve his actions can he? He can choose to retcon declared actions when he doesnt like the results of those rolls can he?

 

[robus]

There’s a key bit missing though. IMHO

It's not a house rule.

When a creature (PC or monster) declares a hostile action, the result of which is uncertain, combat sequencing starts (and narrative time ends).

Not all actions are uncertain. and that means violent actions too.

The combat system has been built to “model“ a battle where the outcome has been determined to be uncertain. That’s why we have the bands for evaluating the combat challenge: easy, medium, hard & deadly. Even easy has a tiny chance of going sideways if the monsters get lucky enough. Combats outside of that range are not considered uncertain: too easy ? The PCs crush their foes. Too deadly? TPK or the PCs are easily captured. There is no point in running those combats as the result is certain and the “game“ becomes boring,

So to come back around, combat sequencing starts when the DM has determined that the result of the violent action is uncertain and the rules need to aid in adjudicating the result.

And yes, if the DM wants to kill your character they can do so at any point in any number of ways. But that‘s always been true. With great power comes great responsibility, as the saying goes.

 

[Dausuul]

When a creature (PC or monster) declares a hostile action, combat sequencing starts (and narrative time ends).

Where do the rules say this? Source?

 

[Flamestrike]

Where do the rules say this? Source?

The PHB.

When narrative time ends, and Combat begins (when a creature declares hostilities, or the DM determines a monster is going to attack), surprise is determined, positions established, and then initiative is rolled:

A typical combat encounter is a clash between two sides, a Flurry of weapon swings, feints, parries, footwork, and Spellcasting. The game organizes the chaos of combat into a cycle of rounds and turns. A round represents about 6 seconds in the game world. During a round, each participant in a battle takes a turn. The order of turns is determined at the beginning of a combat encounter, when everyone rolls Initiative. Once everyone has taken a turn, the fight continues to the next round if neither side has defeated the other.

Combat Step by Step

1. Determine Surprise. The GM determines whether anyone involved in the combat encounter is surprised.
2. Establish positions: The GM decides where all the characters and Monsters are located. Given the adventurers’ Marching Order or their stated positions in the room or other location, the GM figures out where the adversaries are̶how far away and in what direction.
3. Roll Initiative: Everyone involved in the combat encounter rolls Initiative, determining the order of combatants’ turns.
4. Take turns. Each participant in the battle takes a turn in Initiative order.
5. Begin the next round. When everyone involved in the combat has had a turn, the round ends. Repeat step 4 until the fighting stops.

After surprise is determined, and initiative rolled for by EVERYONE in the combat, turns are taken in initiative order.

 

[Dausuul]

How is the Assassin seeing the result of the Dexterity check he just made?

He's aware he's in a game is he and can see the results of rolls his player has just made to resolve his actions?

He knows his initiative the same way he knows his hit points. The character is not aware that it is a game and he has hit points. But he is roughly aware of his physical state and how likely he is to survive getting beat on by a monster. Similarly, he is not aware of initiative as such, but he is aware of the tactical situation, which is represented, very abstractly, by initiative.

I mean, are you actually proposing to prevent players from using their knowledge of initiative order for tactical purposes? Good luck with that.

 

[Flamestrike]

Not all actions are uncertain. and that means violent actions too.

Monsters have AC's and Hit Points. So yes, murder is uncertain.

While I see no need to combat sequence out a 20th level Fighter murdering a sleeping Goblin, generally no no murder is automatic.

 

[Flamestrike]

He knows his initiative the same way he knows his hit points.

No he doesnt. In what frigging world does a sniper sit there, finger on the trigger and dude in the cross-hairs and think to himself... 'No wait... not yet - I think I just failed my Initiative roll!'.

Try rocking up to my table and declaring an action, then trying to ret-con it because you didnt like the roll.

Your Dexterity check for initiative is part of you resolving the action, you just declared. Aint no freaking way I would let you take it back because you didnt like the roll.