My preference is “what makes sense”. I’m not a fan of “modern” published adventures because of how much focus they put on combat encounters as how they plot gets advanced. I do think it’s telling that those with the most positive experiences with PF2 seem to be doing their own thing while those running modules have struggled with it to various extents.
I have a hypothesis regarding the combat focus of PF2 adventures, particularly parts 1 of adventure paths.
An adventure path is designed to take you all the way from 1st to 20th level, including actually playing at 20th level, meaning they need to have room for 20 levels of adventuring across 6 volumes. That means 3 1/3 levels per volume, or two volumes of 4 levels each and four volumes of 3 levels each. Each adventure path is 96 pages, and about 2/3 of that is the actual adventure. The other 1/3 are supplementary material that may or may not be relevant to the adventure, like new monsters, city writeups, and so on. This setup serves two purposes: it gives people who may not be interested in that particular AP a reason to keep subscribing anyway, and it lets Paizo have one person write the actual adventure stuff and one or more other people write the supplementary stuff.
But that's tangential – what's important is that each AP gets about 60 pages of actual adventuring, which is supposed to cover 3-4 levels of adventuring. The default is that you level up via XP, and need 1000 XP to level up, so that's 50 XP per page in a 3-level adventure, or 67 XP per page in a 4-level adventure.
If we take Legacy of the Lost God as an example, it opens with a pretty cool encounter where the PCs have to persuade the watch captain to give their circus a place to put on their show and with good conditions, while a representative for a rival circus argues the opposite. The whole thing takes up about two pages in the book, plus one page setting up scenery. That encounter gets you 80 XP, which is something like 27 XP per page.
The next few pages cover the plot assigned to the PCs' circus, which they have to clear of hazards and monsters. This is a section of 7 pages of what's essentially a dungeon crawl, getting the PCs about 600 XP (plus a bonus of 80 XP for finishing it) for almost 100 XP per page. How? Because instead of spending a page describing the details of a skill challenge, the adventure gets to say "Two weak will-o-wisps, see the Bestiary page 6 and 333". In other words, dungeon crawls make for very high XP per page ratios, and that's good when you have an XP quota to fill and a limited number of pages in which to do it.
This problem is then compounded by at least the first two APs being front-loaded, meaning that book 1 covers level 1 to 4 and book 2 covers 5 to 8. That means more XP per page, which means more fights.
I believe they have taken steps to, if not fix, then at least ameliorate these problems. For example, Kindled Magic (part 1 of Strength of Thousands) is a level 1-3 adventure instead of 1-4 (giving more room to roleplaying and dealing with NPCs), and has a greater emphasis on non-violent solutions to things.
To be clear, "ABP" stands for "
Automatic Bonus Progression."
What it means is that all +x weapons and armor, as well as striking runes (which increase damage) and resiliency runes (which are placed on armor and improve saving throws), as well as skill bonus items, IIRC, are eliminated from the game. Instead, PCs are given the bonus at their appropriate level regardless of what weapons and armor they are using.
As I said before, this is predicated on the mistaken belief (shared by many forum posters and discord users) that without level-appropriate gear, playing a PC in PF2 is impossible.
This is absurd, as Dave appears to agree. You can very easily run a low-magic campaign with few or no magic weapons available, on the condition that the DM adjusts his encounter math to make encounters less deadly - generally by lowering the level of adversaries, and avoiding certain foes that can only be harmed by magic weapons.
You need to do a
lot of encounter futzing to do without magic weapons (or ABP). I don't think the biggest issue is the attack bonus, but the extra
damage magic weapons put out.
Striking weapons (usually a level 4 thing) deal an extra die of damage (two dice at 12 and three at 19).
Also, low-magic games that don't compensate in other ways are much harsher on martials than they are on casters. My level 11 sorcerer would be
unhappy if he had to do without magic items, but he'd still have 14d6+6
cones of cold or
dragon shape letting him fight at +22 dealing ~25 points with a primary attack or ~20 with an agile one. The 11th level champion in the same party would be
devastated by losing 2 points of attack bonus, ~5 points of damage per hit, and the
returning rune on his weapon which lets him use Retributive Strike at a short distance instead of just in melee. Martials need magic items not just to be competitive on numbers, but to gain useful abilities.
My advice to folks running homebrewed or adapted PF2 adventures is to avoid adversaries more than one level above the PCs for the first few levels (say, 1-4), stretch up to two levels above them for a bit (say, levels 5 to 8 or 10) and hold off on the really out-of-their league foes until they've graduated into the mid to upper levels of character advancement. Or if it turns out that they are having a cakewalk with what you've been serving up, and then pump up the volume.
Aside from this single caveat about higher-level adversaries (PC level +3 or +4) I think the Building Encounters guidelines work very well.
Yeah, level +3 or +4 adversaries tend to not just have numbers on their side, but to also be strong enough that they shut down most player tricks that would equalize those numbers. If I'm casting
fear or
slow on someone that powerful, they're fairly likely not just to succeed on their save giving me a modest but useful effect, but even
critically succeed thus nullifying the whole attempt.