How do I design an assassination mission, that is a challenge for the rogue, but not impossible for the other party members and requires teamwork? [closed]

Question

My level 11 rogue/assassin player talked to me after our most recent session, because he feels that he cannot play the character as he planned him to be.

He wants to use his rogue abilities and sneak into his targets bedroom when he is asleep and cut his throat. If everything works flawlessly there are no alarms and he can get out unseen.

The problems I see are the following:

1. When sticking to the combat rules of dnd-5e there is a chance, that some characters can not be killed outright. (This problem can be solved, by simply not sticking to the combat rules, though I feel that there has to be somewhat of a challenge. Not simply one good stealth roll and you are basically done.)
2. If the target is asleep and is not the kind of person who has security measures or guards but still somehow is a chosen victim of the party. How do I make it interesting? A rogue with his reliable talent and double proficiency in stealth and sleight of hand is basically undetectable for him. I think it feels unsatisfying if we just streamline everything without making rolls.
3. If I increase the challenge by higher DCs, more NPCs and more security measures, that would probably make it a challenge for the rogue, but it would become nearly impossible for other characters. How do I increase the challenge otherwise?
4. Even if it would be a challenge for the rogue (which would include very high perceptive guards and/or other security measures) he would have a higher chance doing everything single-handedly, than taking his party members with him. Even though in our group every character is proficient in stealth, they do not have the reliable talent feature. So there needs to be a reason why the party members come with the rogue, even though they are not as good as him in sneaking

So my goal is to design an assassination mission, that

• Is a challenge for the party and does not only consist of one stealth roll but also is not impossible for the less sneaky ones.
• Is interesting by itself, and doesn't feel as a time filler.
• Includes the whole party (Assassin Rogue, Gunslinger (Homebrew), Conjuration Wizard), because they are all required and even though they are not as good as the Rogue, there is still a good reason for them to participate.

Answer 1

Make the actual attack only be part of the whole 'job'.

The actual assassination should only be a small part of the entire adventure. Otherwise, like you said, it comes down to die rolls and is relatively boring. If someone is worth assassinating, then they probably have means and a certain degree of awareness. They would also most likely know that someone is hunting them, and would thus take measures to prevent being taken out from an open window. That is where you build in your challenges that can check off all your boxes.

The Settings

If the person you're after lives in a one bedroom house in the middle of nowhere, then the mission is easy and boring. Instead, put them somewhere more difficult to get to:

• A floating tower 100 feet in the air is great, because then your Rogue will need the assistance of the rest of his party to get up to it, and the Wizard can feel like a cool person.
• An underwater cave guarded by sentient porpoises that enjoy wrestling would make for a fun skill challenge that the fighter could help with
• A bog-standard stone keep (maybe overgrown with lecherous plants that will sound the alarm unless they're flattered?) will mean lots of small encounters need to be navigated before getting to the main event

The Target(s)

I'll be the first to admit that a level 11 rogue isn't really objectively all that powerful compared to other classes in 5e, but a level 11 character is supposed to represent one of the best specimens on the planet, and as a DM it's your job to make the players feel powerful (even if they really aren't). The way the book is written, a level 11 character shouldn't really be going after regular mooks. That would sort of be like sending navy SEALs against jaywalkers. Instead, your targets should be powerful in at least one way to justify their being a threat. They should be extremely strong or intelligent or charismatic. They should have resources and they should be able to anticipate threats and react accordingly. They should have assets they can call on for help.

The strengths that the targets have are what make the mission interesting and fun and challenging. Give your targets abilities like blindsight or blindsense to make sneaking up on them harder, give them elite guards with high perception, have them have decoys all around their compound, make them actually be shapeshifters who usurped the position of the person your players think they're targeting. Give them something that makes them special, which in turn lets your players feel special when they finally win.

The Challenge

You said you have a rogue, a conjuration wizard, and a gunslinger/fighter homebrew. It looks to me like you have a range-heavy party with skirmisher tactics and moderate single-target damage (depending on what your wizard has for spells). Given this, build your encounters based on that. If the fighter has a high STR, make situations that call for a high strength check. The rogue is most likely a DEX rogue so they'll need help if something heavy has to be lifted, which makes the fighter feel powerful. A conjuration wizard probably has Fog Cloud in their spellbook, so put the players in situations where they absolutely cannot cross an area without something blocking vision. Then your wizard can 'save the day' by letting the rogue and fighter get further into the compound.

The Complaints

From your description of your players, it looks like at least some of them aren't going to like this. The rogue seems like they would be 100% happy to just stealth in, do the deed, and leave for the entire game. You need to find a way to do this while not making everything trivial. For instance, maybe you could have the main target have three vassals that need to be dealt with, and one or two of them can be taken care of 100% stealthy by the rogue. Then the rogue is a hero, but doesn't shut down your entire idea.

You can also look at the rules for stealth in the book for guidance. You keep mentioning that the rogue can use reliable talent to always beat stealth checks, but I would recommend you to read the stealth section again. Stealth is relatively weak in 5e, it's difficult to get, even harder to maintain, and even the world's greatest rogue will never really be all that great at it. A level-11 rogue certainly can't expect to pass every stealth check they come up against, and in fact if you put 4 or 5 guards in the room looking for them, the rogue is almost guaranteed to fail against at least one of the active checks. The archetype of 'sneak anywhere and never be detected' isn't really mechanically possible in 5e using the book mechanics. Not only is stealth difficult to maintain even in normal situations, there are a variety of ways to defeat stealth 100% of the time with spells (true seeing, fairy fire, etc), monster abilities (blindsight, blindsense, tremorsense, true-seeing, etc), and even basic mechanics (it's not possible in 5e to stealth across a well-lit room without the invisibility spell). A few torches makes it mechanically impossible to stealth past guards in most circumstances (especially if your smart target sleeps in a room with one heavy, well-lit entrance and a few guards).

I think optimally, you should look at your player's abilities and come up with situations that only one of them can solve. Then put those together to form your mission, and that way everyone needs everyone else, and the payoff is rewarding instead of boring.

Answer 2

If the target is a high-level character he will most certainly not be able to one-hit kill him even with his rogue abilities. How would I explain this cinematically, that even though he was unseen, even though his prey did not have a clue he is going to kill him, the rogue was unable to cut the evil guys throat?

Why can't he? I think the problem here is that you're using the combat rules to solve a non-combat situation. Sure, the rogue probably cannot produce an attack damage roll which takes enough HP's to kill a high-level character... but remember, hit points are not "life points". When you attack something and you do X "damage", in fact, you haven't hurt it at all. Hit points represent fatigue, skill, willpower and anything that can make you lose a combat when you run out of. When a character falls to 0 hit points it means that it is hurt - usually for the very first time in the whole combat - and killed (if it's a NPC) or at least knocked unconscious and making death saves.

All this rules only apply if the character you're trying to kill is trying to avoid it (and probably trying to kill you instead). If an assassin enters a room without being detected, gets close to its target without awakening it and makes a good roll on dealing a cutting-throat blow... well, the target is dead. No combat at all. At least in my table.

EDIT: as per making an interesting assassination mission, I'd suggest a two way approach. First, how to get in (main protagonist, the assassin, but he will need help from the rest of the party), then, how to get out - and there's the point where the rest of the group have the spotlight.

Answer 3

If everything works flawlessly there are no alarms and he can get out unseen.

If it can go wrong, it will!

• A river has burst its banks and the only option seems to be the front entrance.
• Opening the one known entrance wakes the target up - but the target has a means of escape.
• The party don't know exactly where the target sleeps, and must try multiple locations at the same time.
• The party need to work together not just to eliminate the target, but to conclusively frame someone else.
• The target needs to disappear. That means hiding the body.
• It turns out that the target is sneaking out to perform their own evil deeds.
• The target has information that someone else wants - they're kiddnapping the target.
• The target has information that you need - you need to kidnap them (or if you're really good, persuade them to come with you) while someone else is trying to silence them.
• The target has allies who have set up alarms or defences.
• The target happens to live with someone (or has a visitor) who does have their own security which the party must contend with.
• Outside the room, the party overhears the target with a visitor, and following the visitor suddenly becomes the priority.

Time pressure is important. You want to avoid situations where the party decides "let's come back tomorrow". Moreover, if you make it too obvious too early that it's going to be tough, the party will try to find other times of day the target is alone, which could lead you to doing a lot of work. You want to take care to get the balance just right - reward some planning, but don't make it too easy.

Alternatively, have you considered establishing early on that they sleep somewhere very secure and that the best opportunities are when they're doing something else?