Pathfinder Essential Books and Supplements to Buy
The Pathfinder product line spans well over 100 published volumes across two editions, which is either exciting or paralyzing depending on how long ago the shrinkwrap came off the Beginner Box. This page maps the core rulebooks, key supplements, and genre-expanding sourcebooks that actually earn shelf space — organized by what they do, who needs them, and what can reasonably wait.
Definition and scope
A Pathfinder "essential" book is any physical or PDF publication from Paizo Inc. that provides rules, setting material, or mechanical options players and Game Masters use at the table. The category breaks into four types: core rules (foundational mechanical text), player options (expanded ancestries, classes, feats, spells), GM resources (encounter tools, monsters, world-building support), and adventure content (published scenarios and Adventure Paths).
This page focuses on Pathfinder Second Edition (released August 2019), which replaced the original 2009 ruleset. For a full breakdown of the differences between the two systems, the Pathfinder First Edition vs Second Edition comparison covers the mechanical shifts in detail.
How it works
Paizo publishes in predictable release cadences. The core line (hardcover rulebooks) forms the structural spine. Supplements layer on top with optional content. None of the supplement material is required to run a complete campaign — but the right books meaningfully expand what's possible at the table.
The three books that form the mandatory foundation:
- Pathfinder Core Rulebook — 638 pages covering ancestries, classes, skills, spells, combat, and the game's fundamental resolution system. No other book is functional without it. A full overview of the Core Rulebook breaks down what each chapter actually contains.
- Bestiary — 360+ stat blocks across a standard monster index. GMs cannot run encounters without creature data, and the Pathfinder Bestiary and Monsters reference covers how to use them effectively.
- Gamemastery Guide — 258 pages of encounter design, NPC building, variant rules, and campaign tools aimed specifically at GMs. The Pathfinder Game Master Guide page expands on what's inside and who it's for.
Everything else is optional but not arbitrary.
Common scenarios
The supplement that's right depends heavily on the table's situation. Three distinct buying patterns appear consistently:
New group, one GM, three to five players
The Core Rulebook is the single required purchase. One copy shared at the table is functional; players who want home reference benefit from a second copy or the PDF. Paizo sells the PDF version at a lower price point than the hardcover. The Pathfinder Beginner Box is an alternative entry point at a lower cost — it strips the system down to its most accessible mechanics and comes with pregenerated characters.
Established group expanding player options
The Advanced Player's Guide (released 2020) added 4 new classes — Investigator, Oracle, Swashbuckler, and Witch — along with expanded ancestry options and hundreds of new feats. It's the most widely used supplement after the core three. The Player Core and Player Core 2 volumes (released 2023–2024 as part of Paizo's remaster project) reorganize and update core player content to remove third-party IP holdovers, and they functionally replace the original Core Rulebook for tables starting fresh.
GM building a homebrew setting or long campaign
Secrets of Magic (2021) adds the Magus and Summoner classes while significantly expanding spellcasting options — useful for campaigns leaning into arcane or occult themes. Book of the Dead (2022) focuses entirely on undead creatures and mechanics, including rules for playing undead characters. The Pathfinder Golarion Setting material — particularly the Lost Omens line of sourcebooks — provides the world-building infrastructure for Paizo's official campaign setting, spanning city guides, faction sourcebooks, and regional atlases.
Decision boundaries
The sharpest buying decision is between breadth and depth. The Core Rulebook plus the first Bestiary cover roughly 85% of what any table needs to run Pathfinder indefinitely. Every supplement beyond that trades money and mental overhead for expanded options — a trade-off that scales with how much the group enjoys mechanical variety.
A second useful contrast: official supplements vs. adventure content. Hardcover rulebooks and sourcebooks are permanent references. Adventure Paths like Abomination Vaults or Kingmaker are one-use narrative investments — enormously valuable if the group plays them, worth nothing if they sit unplayed. The Pathfinder Adventure Paths page covers which campaigns suit which group sizes and experience levels.
For groups running organized play rather than homebrew campaigns, the Pathfinder Society Organized Play program has its own book access rules — certain supplements are legal for Society play, and the admissibility list is maintained publicly by Paizo at paizo.com.
One structural note worth knowing: Paizo provides the full rules text for Pathfinder Second Edition free through the Archives of Nethys, the official rules reference site. The physical and PDF books are useful for layout, art, and offline access — but the rules themselves are not paywalled. That changes the calculus somewhat. Buying a supplement is buying a curated, readable presentation of rules that are otherwise free to access in raw text form.