Vendors
Everyone who sells you something. Stock is read from the items themselves, so it matches what each item page says about where to buy it.
Blacksmith and crafter
Upgrades and rune work.
Questlines
People whose story goes somewhere. Six of them end in a fight, and those link to the boss page.
Not quite people
Read this before you start any of them
Most failed questlines in this game trace back to one of five decisions. 15 of the 20 NPCs here have a walkthrough, and every one of them can be broken by something on this list.
Five Radiant Beacons sit behind Sentinel bosses: Forsaken Fen, Upper Calrath, Fief of the Chill Curse, Tower of Penance and The Empyrean. Killing the boss and cleansing the beacon are separate actions. The instant you cleanse one you are committed to the Radiance ending, Inferno and Umbral become impossible, and Damarose turns hostile. Kill the Sentinels and walk away from their beacons to keep your options open.
Paladin Isaac, Kukajin and the Tortured Prisoner all want to be summoned at the final Lightreaper fight, and you get one summon. Choosing Isaac fails Kukajin permanently and the reverse. Decide before you enter that arena.
Stomund, Exacter Dunmire, Thehk-Ihir, the Tortured Prisoner and Damarose each shut their shop permanently at a specific step. Spend your Vigor before you hand the item over, not after.
Several characters — the Iron Wayfarer worst of all — move when you sit at a vestige, not when you clear an area. If someone is not where they should be, rest and look again, and check the Umbral realm.
Three are quest guillotines: the Fief of the Chill Curse door kills Drustan's quest if opened early, the church gate to The Empyrean removes Thehk-Ihir and Stomund, and the Bramis Castle gate forecloses the Umbral rune handoff. Do the local business first.
Where the sources disagree
7 places where the sources behind these walkthroughs contradicted each other. They are listed rather than resolved, because picking a winner we cannot verify is worse than saying we do not know.
Where this comes from
The roster is the game's own: it keeps a UI record for every character it treats as an NPC, and this is all of them. Shop stock is read from the items, so it agrees with what each item page says about buying it. Locations come from the quest-step spawners standing in the game's levels — which is why an NPC who moves shows the whole route rather than one address. Datamined
The walkthroughs are the exception and are labelled as one. Steps, triggers and fail states are confirmed in play — the game files record quest steps but not reliably what advances them, so a step-by-step cannot be datamined. What the build does check is every reward they name: 65 of 66 resolve to items in our own data, and the one that does not is a consumable we have never ingested rather than a claim that is wrong.