So I asked my fictional, somewhat sarcastic, hyperbolic and passive aggressive Adventurers' League Encounters table these questions - their answers follow.
Oddly they all had different answers (H. represents the "Kobayashi Maru" answer).
Question 1a: The Prince Battercap (Noble 8, AC 13, 51 hp) is being held by the Vladessa the Assassin (Rogue 6, AC 16, +7 Attack for 2d4+4 +6d6 on an Assassinate sneak/+3d6 normal) with a knife to his throat. She threatens to kill him if the party tries to prevent her escape. Which do you prefer to happen (you are a party member)?
A.) The villain is allowed to back away out of the room after some witty banter, throws the prince down and escapes.
B.) The villain backs away, slits the prince’s throat because the party let her, and the party chases her down.
C.) The party attacks because the Assassin can’t Assassinate since no one is surprised and can’t one shot the prince anyway (average damage 40 vs. hp 51).
D.) Play stops while we poll the message boards on how this should be resolved.
E.) Roll initiate if the party wins they take her down before she can act, if the assassin wins she saws on the Prince’s throat for 17 damage (dagger plus sneak) fails to kill him then gets cut down.
F.) Situation won’t happen because the Prince won’t be in that situation if he still had positive HPs. If the Assassin had already reduced him to 0 hp with a successful attack and chosen to take him hostage instead of killing then it could happen.
G.) Situation won’t happen because the Prince would already be dead. The assassin would have already moved full plus Dash from Cunning action, then taken the hide action behind a bystander (because all rogues are halflings) to become effectively invisible.
H.) Insert your Option here.
Question 1b: Your character Prince Battercap (Fighter 8, AC 17, 60 hp) fails a Will save versus Hold Person from an assassin's ally Enchantro and is subsequently being held by the Vladessa the Assassin (Rogue 6, AC 16, +7 Attack for 2d4+4 +6d6 on an Assassinate sneak/+3d6 normal) with a knife to his throat. She threatens to kill him if the rest of party tries to prevent her escape. Which do you prefer to happen?
A.) The villain is allowed to back away out of the room after some witty banter, throws you down and escapes.
B.) You wait until you succeed on a Will save versus Hold Person and then succeed in breaking the Held condition continuing the fight.
C.) The party attacks because the Assassin can’t Assassinate since no one is surprised and can’t one shot your character anyway (average damage 40 vs. hp 60).
D.) You tell the party to shoot the hostage. They do and you take 45 damage. Vladessa is not surprised (Alert feat) and finishes you for another 17 from the sneak with advantage. Fortunately you get better after a short rest.
E.) Roll initiate if the party wins they take her down before she can act, if the assassin wins she saws on your throat for 18+4 damage (short sword plus sneak and a twf for another 4) fails to kill Battercap then gets cut down (no assassin uses a dagger – they dual-wield short swords).
F.) Situation won’t happen because the Prince won’t be in that situation if he still had positive HPs. If the Assassin had already reduced him to 0 hp with a successful attack and chosen to take him hostage instead of killing then it could happen.
G.) Situation won’t happen because the Assassin would already be dead. The party first strikes anything that might be a threat. Four greatsword attacks at +8 for 2d6+5 with action surge make short work of him against his weak DPS.
H.) Insert your Option here.