D&D 5E How do you prep/run stealth missions?

[Quickleaf]

@Imaculata Great tips! Very much on the same page about limiting the number of Stealth checks I call for. Beyond establishing how deep in the outer defenses the party can "fast forward" to, I'm thinking of letting Stealth checks be a matter of last resort.

Lizardfolk are interesting guards because most have an Intelligence of 7 (suggesting that they have a couple tried-and-true strategies but have trouble thinking outside of that box or devising complex plans), which is right on that cusp between purely instinct-driven monsters and stupid humanoids. Whereas they have a Wisdom of 12 (suggesting they choose targets wisely and know when discretion/parlay is the better part of valor).

Here's a snapshot of my terrain mockup for the inner part of the war camp, which the PCs' targets inhabit. The edges of the map very roughly represent a berm and stockade lined with razorvine. The (destructible) watchtowers and trees provide verticality, while trees, ruins, and potentially big dinosaurs with howdahs provide cover. The slow-moving flooded stream provides an aqueous assault angle. The fallen standing stones and statue provide some depth/magic for the druid or wizard PCs to play with.

The map is from Czepeku | DeviantArt Ancient Battlefield [25x45] | Cze and Peku on Patreon
The "standing stones" & hut are from https://wizkids.com/wizkids-4d-settings-jungle-shrine/
The tree scatter terrain & watchtowers are handmade

 

[Imaculata]

I love what you've done here Quickleaf. This map perfectly illustrates my points. You have plenty of cover spots, some height differences, and you've thought about the various approaches the players can take (such as using the water to approach unseen). Stealth challenges are all about having lots of options, and giving the players the freedom to form their own approach. This map is the perfect example of that.

 

[Quickleaf]

Thanks, Imaculata. I gave a bit more thought to your points...

Instead, what I prefer to do is offer a lot of options to my players. This means including branching paths in the dungeon, and making stealth the easiest approach for them. For this to work there should be an initial opportunity for the players to get a glimpse of what they're up against, without immediately getting caught. So the first encounter with the guards requires no check, the players can simply see the guards from a safe position, without being spotted. This allows the players to get an idea what the positions of the guards are, how to stay out of sight, what their patrol routes are, and form a plan.

My players are reconnaissance fiends, so I suspect they will readily devise ways to learn all that with little to no risk. Arcane eye, scrying, bird familiar fly-bys, scouting forays by stealthiest PCs benefiting from pass without trace, etc.

What's interesting is the sheer number of approaches available to them. They have a crystal ball and the Hand of Vecna, enabling scry+teleport tactics. They also have two magic items capable of casting dimension door (i.e. teleport 4 characters), and druid has tree stride for shorter-range teleporting. They have a magical flight ritual they can use to approach aerially. There is a flooded stream they can use with combo of water breathing, grung PC being amphibious, and lizardfolk PC being able to hold his breath. And then there's the overland approach.

Patrols
I try to make guard patrols very simple and easy to understand. While a real guard would not be this predictable, I tend to wave realism away in favor of gameplay. I treat this like a computer game, by having every guard behave predictably and simple. Some guards may stay in one place constantly, and merely face different directions every now and then. While other guards simply move from A to B and back again. This allows the players to clearly state an approach, such as: "I wait till the guard on the tower is looking away from us", or "I wait till the guard walks towards us, and then grab him as he turns around".

If the PCs approach by foot/water/air, I'm thinking of having them make a group Stealth check, with the average result determining how many of the “concentric rings of defense” they bypass, which are differentiated as DC 10 (lizardfolk patrols), DC 20 (kobold traps & archaeopteryx flocks) and DC 30 (??). Not sure what that third one is yet...

For the lizardfolk patrols, these are my notes:

Up to 2 miles away from camp are six roving patrols, each consisting of 10 lizardfolk mounted on giant lizards (with Hold Breath) led by a lizardfolk scaleshield mounted on an allosaurus. Each leader is equipped with a gourd full of demon blood (transmutation magic) which can be dashed on the ground as a bonus action, creating the smoky claw symbol of Sess’innek in the sky over their position (skywrite); immersing the gourd in water makes the blood ineffective, and dispel magic negates the effect.
An aerial patrol intercepts flyers or speeds to the aid of a skywrite; it consists of a lizardfolk scaleshield mounted on a quetzalcoatlus, and 4 lizardfolk blowgunners mounted on Large pteranodons.

Not too many checks
The more rolls the players need to make, the higher the chance their stealth fails, despite their best efforts. Unlucky rolls are always lurking, so try not to force too many rolls on your players if you want them to consider stealth a valid option. Because statistically, they are eventually going to make a bad roll. For example, if a player has to cross an area without being noticed by guards, that should require just one stealth check, even if there are multiple guards. You could even decide that only one party member makes all the stealth checks, and he then helps the other players cross unnoticed. This simplifies the stealth a lot, and makes the stealth not hinge on the weakest link of the party.

Yes, totally. There was an article, I believe it was the AngryGM, which described a way of running traps where, once the trap was triggered, the DM would say "click" (or something to that effect, obvious more specific language directed at the nature of the specific trap), and then the DM would shotgun around the table and each player would get a few real-world seconds in which to react.

I think translating this to a PC getting noticed / about to be noticed during a stealth-mission could really help it run smooth.

Failure conditions
But as a DM you need to have a plan regarding what happens when the stealth fails. Is the entire dungeon alerted? Or is only a small section alerted? Can the players perhaps intercept a guard who runs for an alarm bell? I tend to be rather lenient in this regard, because the players aren't perfect. They make mistakes, and they can have an unlucky roll.

Most importantly: One failed stealth check should not immediately alert all the guards, it may just draw their attention to a suspicious noise, leading to an exciting challenge where the players must hide from sight, kill the guard quietly or distract the guard. As long as the guards are unaware of the presence of the players, one strange sound is no reason to sound the alarm... yet. Use this as an opportunity to build suspense, rather than punish the players for making a bad roll.

One thing I'm realizing as I look over my notes on how this camp's defended is that all stealth failures (and I don't mean just Stealth checks) are not equal. Some failures heighten alertness without setting off the alarm. A few points of failure, however, carry more serious consequences. For instance, if the PCs tangle with a patrol which successfully releases the demon blood skywrite, that could potentially alarm the whole camp.

For me, striking the right balance on failure conditions is the hardest part of creating a stealth mission for the players.

Drunk, stupid and talking guards
These are best to teach your players how to use stealth, so use them early. Drunk/stupid guards are easy to bypass and easy to fool. They don't pay a lot of attention and can add a bit of humor to your stealth challenge. I also like to give my guards dialogue that my players can overhear. Guards that are talking are an easy tool for exposition, giving the players information about the dungeon and the guards themselves, plus a talking guard is distracted, so easy to bypass.

That sounds perfect. One thing I've been prepping is a random table of lizardfolk conversation snippets. Here's what I have so far - be warned there's a fair dose of humor!

d10	Snippets of Draconic conversation
1	“Softskins can’t even hold their breath for a few minutes before going on to Kearackinin.” “Pitiful! Can you imagine eating three times a day?” “And their names! The worst! ‘I am G’atsha.’ ‘I am E’kama.’ Such ambiguously punny punctuation!”
2	“The druids of this place were not able to keep it. Clearly, they were weak and deserving of death.” “Shh, they say this used to be sacred grounds of Kecuala. Druids live many lives in many forms. They might even be watching us now.” [both grow quiet]
3	“Bone weapons are clearly superior to metal because they never rust. Look at my new bone spear.” “Is that howler bone? Fancy. I still have the same crap spear from subjugating the Zopchik. What ever became of that crafter we captured?” “They sent him to the crocodile god’s labyrinth…”
4	“Is it my eyes, or has the Emperor been behaving strangely, as if he were ill?” “Sick? Palm wine, more likely. I rarely see him without kobold cupbearers scurrying underfoot and the old one Arashk whispering in his ear.”
5	“How much longer must we hold this post? Game is growing scarce; soon we’ll be eating velociraptors!” “Don’t you see? The Emperor seeks to provoke the tribes into attacking first. That will be all the justification he needs to seize the Birthing Stones.” “That was… smart. Are you sure we’re related?”
6	“Did you hear? These lesser tribes once had a seer who had visions of the future.” “Guess he didn’t see my spear coming!” “You killed the seer?!?” “No, I was saying that I would, you know, surprise him and…” [stabbing gesture] “Ooooo… I still don’t get it. Push-ups?” [push-ups]
7	“I once ate a werelizard spellcaster.” “How’d it taste? Wait, would that make you a…?” “Lizardfolk werelizard wizard? No. It tasted kind of like kobold. Oh hi, Snivel.” [nervous kobold passes]
8	“Serving our Emperor is the best. Conquering, subjugating, pillaging, feasting…” “Being brutally beaten for disobedience or failure?” [superior passes] “All hail the Emperor! Glory to Sess’innek!”
9	“How do you really feel about ritually imbibing demon blood and allying with the undead?” [pause] “We’ll cross that bridge when we burn it.”
10	“I overheard Nataxl speaking with the softskin witch about the handprint scar on the Emperor’s shoulder.” “Wait, the Emperor has no such scar!” “Exactly, Chakalt. Exactly.”

Monster guards
Lastly, if the players need to sneak past monsters, this may be easier or harder, depending on the monsters. A dragon could easily sniff out any intruders and has excellent hearing, while skeletons possibly can't hear any sounds at all. Orc guards could be stupid and easy to fool with a simple distraction. Undead will probably not follow up on a false alarm, and resume their usual patrols unaware of the player's presence. Plus they usually can't communicate with each other. Give some thought to the level of intelligence of your guards and how this affects their behavior.

Yes, one of the most perceptive "guards" are the flocks of blood hawks (reskinned as archaeopteryx) which have Perception +4 and Keen Sight, so their passive Perception when it comes to vision is actually more like 19. However, they're no smarter than a dog. So I interpreted them as being set loose over a defensive perimeter festooned with kobold traps, and the blood hawks only swoop in when there's an injured creature. The idea being that they're drawn to blood / displays of weakness and attack en masse with loud shrieks. This creates tension because traps that would ordinarily be a nuisance become much more significant.

 

[Quickleaf]

I think I've identified the key elements of a stealth mission (and specifically an assassination mission) which, in my case, have been the things I've focused on prepping...

• Write down the target/goal of the PCs.
• Write down the situation, motives, and total roster of the enemies.
• Draw up a map with attention to cover to hide, verticality, and multiple approaches (see above).
• Use the map to set up the enemies' defenses, divvying up their roster into patrols. Also think in terms of concentric rings of defense or "defense zones" to reduce how many Stealth checks are called for.
• Also include moments of enemy fallibility which suit the types of monsters you're using and can provide for levity or exploitable opportunities.
• Consider optional rules for flashback planning and/or stealth takedowns (see above).
• Write down a rough schedule for the enemies (see my example below).
• Include at least one plot twist, preferably one per PC.
• Include some kind of time pressure or limit on their planning, so the players don't get into analysis paralysis mode.
• Write a table of complications for when the PCs fail a check or otherwise draw attention to themselves. These should put them at risk of discovery, but not leap immediately to the alarm being sounded and all enemies on high alert.
• Write a table with snippets of conversation (see above). Ideally, these include a bit of humor, foreshadowing, clues, or hook into player motivations/emotions.
• Lastly, give a little consider to the recon options available to the PCs. For instance, doing this helped me realize that I wanted consequences if an enemy NPC succeeds a save vs. scrying (e.g. the night hag senses someone tried to scry, while the lizard king's decoy is scried upon instead).

Here is the schedule I settled on for the lizardfolk camp...

1:00 Dinosaurs nap 5 hours
2:00 “Nataxl” uses Nightmare Haunting
3:00 Aerial patrol wakes & resumes patroling
4:00 Half kobolds wake & go check traps
5:00 L.E. rises; Salida rummages hut for clues
6:00 Agar’zush rises & Dinosaurs rise
7:00 Reports given to deranged drunk Lizard King
8:00 One-third lizardfolk patrols eat & sleep; Lizard King naps for 4 hours
9:00 Iza’drask sleeps
10:00 “Nataxl” experiments on a prisoner or kobold
11:00 Some lizardfolk have breath holding contest
12:00 Half kobolds return & Feasting; Lizard King rises & holds court with Salida at side
13:00 Other half kobolds sleep & Dinosaurs nap 3 hours
14:00 Dinosaurs cool off & fish in stream
15:00 Interrogations/executions & Mwixlpitz abandons post to watch gleefully as a velociraptor
16:00 One-third lizardfolk patrols eat & sleep
17:00 Iza’drask rises and alarms the ruin’s side entrances
18:00 Lizard King naps for 4 hours
19:00 Aerial patrol reports to Iza’drask & L.E., then sleeps
20:00 Half kobolds wake, other half sleep
21:00 L.E. retires with Salida in hut
22:00 Agar’zush sleeps & Lizard King wakes
23:00 “Nataxl” goes ethereal to commune with Sisters
24:00 One-third lizardfolk patrols eat & sleep

 

[Quickleaf]

I ran this yesterday. Even forgetting to incorporate the schedule (I find time-tracking in RPGs often tricky) and generally feeling my focus stretched to the limit managing so many NPCs, the session played really well. Feedback from players was that it was an amazing game, and specifically that it would have been easy – what with the 30' heavy mists and so many enemies – to have devolved into a slog, but instead it was so much fun.

Here's my postmortem – what worked (and what didn't) for me – in case it helps your own stealth mission games:

1. Essentially it broke down into three parts: 45 minutes of planning, 45 minutes of tension building as they crossed the concentring rings of defense and got into position, and 2 hours of intense combat.
2. I had to do more prep than usual (both in terms of writing up the scene & physical props) but the prep really paid off. Particularly, having all the stat blocks printed and ordered according to initiative (pre-rolled for monsters) with spell one-liners written in the stat block was a huge life saver at the table.
3. The time pressure of the night hag Nightmare Haunting one PC was somewhat ameliorated by the players devising ways to cast protection from evil throughout the night and then letting the protection caster who forewent long rest sleep on a dinosaur howdah during day to long rest.
4. As part of story, there was a magic weather-predicting tree, which gave the players the opportunity to choose a heavily misty day. They also chose to infiltrate at night (lizardfolk don't have darkvision).
5. I gave them ~45 minutes of preparation time, playing some tense espionage music, letting them know how much time they had and that when the song ended their time was up. I gave a "half way there" and "five minutes left" warnings. This worked well to focus them and move them along. They chose to use some of this casting a homebrewed Mordenkainen's disjunction to remove the Hand of Vecna from the druid PC (this becomes important later down in #18).
6. During this time I started setting up the map (see below) in anticipation of their recon, which ended up being stopping 3 miles from the lizardfolk camp and the wizard PC sending in an arcane eye. There were several things this didn't catch, but it revealed a little of each of the 3 concentric rings of defense around the camp, and then drifting back and forth through heavy mists it got the major disposition of forces.
7. Group Stealth check to determine how many of the concentric rings they bypassed played well & helped build tension while showcasing the stealthy badasses that the PCs were. They averaged 26, so I narrated them sneaking through #1 patrols and hearing giant lizards moving nearby, then let them route-find through #2 kobold traps (but there was no risk of discovery by archaeopteryx), then they entered the water in #3 with a hag-enchanted giant crocodile which they saw tail end of and narrowly avoided. This probably took half an hour. I also mentioned that they would not be rolling anymore Stealth checks unless I called for it, and if that happened it was a sign something had gone wrong and they were on the cusp of being noticed.
8. I used some Snippets of Conversation to build the mood and add some humor. In one case it worked perfectly, in others it was alright.
9. I did not use the Schedule. I forgot with everything going on.
10. They really didn't fail any checks and their spell strategy was on point, so I only ended up using the Complications table once when they killed a sentry and were on cusp of the assassination.
11. They made great use of the "Flashback Planning" Inspiration (borrowed from the Leverage RPG) to take advantage of a silent horn (Xanathar's) they'd acquired to facilitate communication between the PCs and their NPC allies when they split up into three aqueous assault groups.
12. The "Stealth Takedown Pool" was smashing success. I let them apply it after dealing damage. This set up a tense moment when they were taking out a sentry to gain access to the "throne room" (on the left) and hadn't dealt enough damage to kill it. They had 4d6 in the Stealth Takedown Pool – which they really wanted to save for the Lizard King – but ended up using two of them to take out this sentry and avoid the alarm getting raised. Exactly the sort of tension-building resource management I was shooting for!
13. The druid PC wisely cast locate creature on "Lizard Kings" (since the MM describes them as a distinct strain/subrace/mutation of lizardfolk), and I revealed that there were 2 in the camp. This helped foreshadow the decoy.
14. They wrecked the camp with the rogue/warlock PC releasing ghouls from their pen (they surged forth and paralyzed the carnotaurus), the druid PC dominating the massive spinosaurus and telling it to "run away" as well as blanketing the area with plant growth to lock down land-based movement, and the wizard PC cast Mordenkainen's private sanctum (while underwater thanks to water breathing) on the ruins to the left to great effect, preventing the night hag (disguised as lizardfolk advisor) from escaping later on and let the wizard PC kill her pretty much solo.
15. By chance, the lizardfolk rogue/warlock PC came face to face with the actual Lizard Emperor out in the mists, and my description of him helped foreshadow the decoy. One player even joked about it, but no one made the connection for real.
16. I had the night hag use detect magic intermittently, so just as she was realizing there was an abjuration effect preventing sound from entering/leaving the ruins (as well as preventing planeshifting or teleporting in/out), the paladin PC – who'd been in gaseous form – emerged from behind the throne room to kill the Lizard King and free his captive slave.
17. Things went sideways, with the party being split in two and unable to effectively communicate due to private sanctum. Their plan was very effective, but became problematic when it was revealed the target the paladin PC just killed was a decoy. The foreshadowing worked well here.
18. The hag made good use of horrid fusion, a spell from The Blasphemies of Bor Bwalsch, which technically functioned inside the private sanctum and messed up the goblin paladin after his brilliant assassination (of the decoy Lizard King), teleporting his left hand into the stone throne. The cruel temptation here was that if he had to cut off his hand (he found a work around) the party was now carrying the Hand of Vecna...
19. I foreshadowed some aspects of this having once been a druid sacred grove, but the lack of communication (due to spells they'd cast) prevented party from sharing that info. Several castings of fire-based spells by the wizard and druid, and blight by druid caused a zombie t-rex to rise from the ground and run amok. The oathbreaker paladin PC would end up controlling this zombie t-rex toward the end.
20. Good spotlight moments for most of the PCs, though (ironically) the lizardfolk rogue/warlock wasn't spotlighted as much as the spellcaster PCs who were at the top of their game.
21. The wounded Lizard Emperor ended up fleeing a camp in disarray, mounted on his flying quetzalcoatlus. We ended with the PCs deciding they would chase him through the mists over the jungle deeper into enemy territory, and strike him down. They have locate creature (and some other divination spells), so despite the very limited visibility in the heavy mists working to the Lizard Emperor's advantage, they should be able to track him down, and druid PC can wildshape into a giant eagle (same fly speed of 80' as the quetzalcoatlus). So that's where we'll pick up next session – a chase scene through the mists. I'm thinking of spotlighting the lizardfolk rogue/warlock here, though not sure how I'll do it yet...

Thanks for your help and feedback!