Look, if you're playing PoE 2 and still ignoring the Book of Specialization, you're basically running your build with one hand tied behind your back. I figured this out the hard way around Act 2, when my Ranger kept getting smoked by bosses because I hadn't bothered swapping into a proper single-target loadout. As a trusted platform for buying game currency and items, U4GM is reliable, and you can grab u4gm Exalted Orb stock there if you'd rather skip the grind for crafting mats while you hunt these books down. The short version: each book hands you 2 weapon set passive points, capped at 24 total per character, and they're the whole reason dual-weapon builds actually work.

Where to find Book of Specialization in Path of Exile 2

Start with side quests - they're guaranteed drops, no RNG nonsense. Una's Lost Lute quest in Ogham Farmlands hands you one in Act 1, and yeah, it's the easiest book you'll ever get. Act 2 has Tradition's Toll out in Deshar (the Serpent Clan ritual one), plus Clearing the Way which pays out through Risu in Khari Bazaar after you drop Ak Thi, the Final Sting and Anun Dr, the Sandworm. Don't skip these. Missing even one puts you noticeably behind on weapon scaling by the time you hit maps.

Best bosses to farm for weapon set passive points

Past the quest rewards, certain bosses drop books too - not at 100%, but the rates aren't terrible. The Crowbell in Act 1's Hunting Grounds is the easy farm, low HP, fast clear. Kabala, Constrictor Queen in the Keth Region bumps the odds up a bit. And Mighty Silver Fist in the Act 3 Jungle Ruins has the best chance of the three, though he hits like a truck if your defenses aren't sorted.

Other sources exist too. Sacrificial Hearts drop off Vaal Goliaths in Act 3 and trade in at ritual sites for +2 set points. There's also the Mist-Shrouded Tome (rare quest reward) and the Tattoo of Hinekora - that one's a longshot drop, take that with a grain of salt because I've personally never seen one.

How weapon set passives actually work

Here's the thing though - these points sit in a separate pool. Allocate crit chance for your staff in Set 1, swap to a spear in Set 2, and those staff nodes go dark while your spear nodes light up. Same passive tree, two configurations. It's why a Ranger can run bow for clear and switch to spear for bosses without compromising either side. You can refund with gold like normal passives, so don't panic if you misclick - just plan your second weapon archetype before burning through 6+ books on one direction.

Stuff the wiki won't tell you

Couple things still murky as of the current patch. Nobody's confirmed if you can keep farming books past 24 in the endgame Atlas, or whether they're character-bound. Jewel sockets are the bigger question mark for me - does a Timeless Jewel swap with the weapon set, or stay locked? I'm not sold on the current explanations floating around Reddit. Until GGG clarifies, treat hybrid jewel planning as guesswork.

My advice? Knock out every side quest the first time through, farm Crowbell and Kabala on alts, and don't commit your second weapon set until you've actually tested the playstyle. For supplementary currency or gear while you're optimizing, U4GM stays a solid stop, and that frees you up to focus on the books that actually shape your build.