Last time in my series of posts about designing a whole Pathfinder Second Edition adventure path from scratch, I worked out a robust outline for the 3rd chapter, which amounts to an adventure for 3rd level characters that will get them to 4th level. I'm now doing the same for 16th level, because I wanted to jump into this for a low-level adventure and a high-level adventure.

The 16th-level thinking and ultimate outline is below. But I don't want to bury the takeaway of this exercise at the bottom of this blog post. Here's the thing to notice: the process to create my 16th level adventure is the same as my process to create the 3rd level adventure! In both cases, I needed a dozen encounters (ten moderately difficult, two severely difficult). I looked through the Bestiary (and, to an extent, the hazards in the Core Rulebook) for level-appropriate challenges, identified themes in them, and divided them up in groups to correspond with chapters or encounter areas. I then seeded level-appropriate treasure. This is mechanically identical for the other 18 levels. The technical side works out. The artistic elements come into deciding themes and other story-based elements (like connections between the parts). 

For the 16th level adventure, I remember that I plan to use the ongoing demon/dragon threats. I also said that I'd put the encounter with the top devil in the 15th to 17th level range. It makes sense for that top devil to be a pit fiend. As a Level 20 foe, that's a bit too tough for 16th level heroes to face, but makes a Severe encounter for 17th level. So let's put that resolution off to the 17th level adventure, and not tackle it in this one. 

Looking over the Bestiary and Core Rulebook, I see that banshees are in the right level range, as is a neat hazard called a banshee's symphony. So banshees are a good theme here. Another undead that fits in this range is the skulltaker. So there's an undead component to this adventure. I also see lots of cold-themed foes: wendigos, ice linnorms, ancient white dragons, and so on. This all speaks to cold mountains to me, and lets me bring in some giants (rune giants at this level) and powerful elemental creatures like uthuls.

I already know the next level's encounter is going to be with a pit fiend, and I've decided that the devils in my adventure path are more urban. So having this adventure be in a remote mountain wilderness will provide a good change of pace. Looking at my map, I could place this in the upper northwest corner of the map. It's mountainous, and far enough from civilization to have a "here be dragons" feel (literally!).

I looks like I could have an ice linnorm-vs.-white dragon rivalry. Neither of those foes is tough enough on its own, so maybe it's an elite ice linnorm (I'll call him Rimecurse) and an elite ancient white dragon with a rune giant bodyguard (I'll call the dragon Chraxavun). Both are Moderate encounters.

I think it will be helpful to have this adventure lead into the fight against the pit fiend at 17th level, so maybe the heroes are going to the wilderness to get some information. Let's say there was a huge mountain monastery built a long time ago, and this monastery is the only place with records about locating and fighting the pit fiend. So the heroes are coming for information. The monks or hermits or whatever are long gone--in fact, let's say they're dead. In fact, they were elves, and that's who the banshees are. This means the banshees can have allies: golems or other constructs who still serve them in their forgotten monastery. But the monastery isn't forgotten now! Rimecurse and Chraxavun both want its treasures but can't get in, and fight with each other over it. The banshees are caught in the middle.

Let's pick teams, and put encounters into these teams.

Team Banshee (original monastery inhabitants):
Moderate: a banshee's symphony hazard
Moderate: a banshee and 2 elite stone golems (looks like a stone theme, so I'm using these rather than iron golems)
Moderate: a skulltaker
Severe: 2 banshees
Severe: a guthallath (a super stone golem!)

Team Rimecurse:
Moderate: Rimecurse herself (elite ice linnorm)
Moderate: An ice linnorm and an uthul
Moderate: 4 uthul
Moderate: A wendigo and an uthul

Team Chraxavun:
Moderate: Chraxavun (elite ancient white dragon) and a rune giant
Moderate: 2 rune giants
Moderate: a rune giant and 3 storm giants (evil ones, I think)

So! An adventure with this! Let's name the monastery and name the adventure after it. Monastery of Frozen Stone for now.

Part 1: The Mountain Trek
The heroes have learned that an isolated monastery high in the mountains has some lore about their devil problem. They make the long trek, and must deal with environmental problems, but they're high-level heroes and unlikely to be dissuaded by the cold.
Encounter 1: Before they even get to the monastery, the heroes are beset by 4 uthuls. Perhaps evidence the uthuls just killed a storm giant with a slave collar.
Encounter 2: A rune giant named Harlasho comes along, but he doesn't want to fight; he's looking for his escaped slave. (He has 3 other storm giant slaves in tow; they are evil, and fight if Harlasho is attacked.) Harlasho represents Chraxavun, a dragon who fights against an ice linnorm in the area named Rimecurse. The rune giant knows of the monastery, but it's heavily guarded. He uses sending to contact Chravaxun. It turns out Chravaxun knows a way in, and offers to share it with the heroes if they vanquish his rival Rimecurse. Harlasho isn't lying, but Chravaxun has lied to him; the dragon has no intention of providing any help to the heroes (and, in fact, knows of no secret way into the monastery). The heroes can go to the linnorm's crevasse (or maybe even the Linnorm's Crevasse, a proper place name!), or just ignore Harlasho's offer and press on to the monastery. The adventure diverges here.

Part 2: The Linnorm's Crevasse
This is an icy mountain pass, and is a straightforward "dungeon" of locations in the windswept pass.
Encounter 1: a wendigo and an uthul guard the entrance to the crevasse
Encounter 2: an ice linnorm and another uthul live in the valley; the linnorm surrenders if badly damaged and tells the way to Rimecurse's lair (maybe it's Rimecurse's offspring, or younger sibling). It also says that their enemy Chraxavun has claimed the area near the monastery's entrance and can't get in himself but keeps everyone else from trying. This is a clue that the dragon was lying to the heroes, and should probably be attainable only with a really good skill check (Diplomacy or Intimidation) against the injured linnorm.
Encounter 3: Rimecurse is enraged by intruders in her crevasse. She attacks. She also has a great big hoard, and maybe as much as a third of the treasure in this adventure.

Part 3: The Duplicitous Dragon
The heroes come to the area near the monastery, which Chraxavun has claimed as his own. If the heroes come here right away, the giants are hostile; if they come after defeating Rimecurse, the giants allow the heroes to pass, but then betray then and attack if the heroes defeat Chraxavun, figuring the heroes would be weakened in fighting the dragon.
Encounter 1: 1 rune giant and 3 elite storm giant slaves. This is Harlasho, whom the heroes met earlier.
Encounter 2: 2 rune giant hunters and guards.
Encounter 3: Chraxavun (elite ancient white dragon) and a rune giant bodyguard. He lairs within sight of the monastery entrance. He encourages the heroes to use the monastery door, saying it's the easiest way in (it's the only way in, and Chravaxun hasn't used it because he doesn't want to risk himself or his giants to its trap, which he knows is there). He has a lair with lots of treasure, too; maybe another third of the adventure's treasure.

Part 4: Monastery of the Dead
This details the explorations of the monastery itself.
Encounter 1: a banshee's symphony hazard on the monastery door; if the heroes haven't dealt with Chraxavun, the dragon attacks once they've been damaged by this trap. Two Moderate encounters right together is actually Extreme, but we can mitigate this by having Chraxavun's guard take a few rounds longer to arrive.
Encounter 2: 2 banshees guard the entry. Putting a Severe encounter right here serves two purposes: it keeps the Severe encounters from being back-to-back, and it signals to the players that the monastery is dangerous.
Encounter 3: a skulltaker lurks in the monastery's infirmary. Probably some treasure here.
Encounter 4: an open chapel has a banshee (the remnant of the head monk here) and 2 stone golems, which are statues of elves that animate to fight. Probably treasure here as well.
Encounter 5: The library is a huge room, and at its center is a great big statue of an elf head. Locating the information about the devil takes some skill checks. When the heroes have it and seem intent to take it from the library, the stone head animates, rising out of the ground as a guthallath and blocking their way.

I selected treasure from the Core Rulebook using the tables there, just as for the 3rd level adventure. This adventure has larger treasure hoards, and I divided it up as follows:

One the dead storm giant: stone bullet
Rimecurse's hoard: high-grade adamantine maul, ghost dust, major cognitive mutagen, 9,000 gp in coins and gems
Chraxavun's hoard: belt of giant strength, +3 greater striking handwraps of mighty blows, truesight potion, greater bravo's brew, 8,000 gp in gold and gems
Monastery's infirmary: true staff of healing
Monastery's chapel: scroll of foresight, 3,000 gp of fancy adornments and jewelry

Now that chapters 3 and 16 are done, I need to do this 18 more times. That doesn't seem to bad! But I have a few considerations first, like how I'm going to present these encounters and what I'm going to do with the first and last levels. Rather than just have 18 more blog posts like this one, I'll tackle those issues next!