Document Control

Field	Value
Document ID	players-skills-xp
Version	1.0.0
Status	approved
Confidence	Medium
Category (track)	Players
Build	both
Owner	PZ Knowledge-Base Pipeline
Created	2026-07-30
Updated	2026-10-08
Review due	2027-01-07
Game versions verified	41.78.16, 42.20, 42.21

Executive Summary

This document is the Players-track deep dive on the skill system: how experience points (XP) turn into skill levels, why Strength and Fitness follow a different scale from everything else, how the starting-level XP boost quietly decides which skills are worth levelling for the rest of a run, how skill books multiply your training rate in two-level bands, and exactly which skills exist on each build. Its parent, players-foundation, sketches the system in two paragraphs; this document carries the full numbers and the full per-build roster.

The headline change between builds is the roster itself. Build 41.78 has 26 skills in six categories [5]. The Build 42-era page for the same system lists 35, adding seven crafting skills (Blacksmithing, Carving, Glassmaking, Knapping, Masonry, Pottery, Welding in place of Metalworking), three animal-economy skills (Animal Care, Butchering, Tracking), and renaming Farming to Agriculture and Sprinting to Running [4] [9] [11]. The levelling mathematics — per-level XP requirements, the 25%/100%/133%/166% starting-level multipliers, and the ×3 to ×16 skill-book bands — are documented identically for both builds, but the wiki's figures were established on 41.78.16 and have not been republished as a verified B42 table [4] [5] [6].

Document confidence is Medium: the release spine and one 42.20 patch fact are primary-sourced, but nearly every hard number rests on pzwiki page revisions versioned against 41.78.16 or unstable-era 42.x, none individually re-verified in-game on 42.20.

Key Takeaways

• Skills level from 0 to 10; each level needs its own (non-cumulative) XP amount, and a regular skill costs 32,775 XP total to master while a passive skill (Strength/Fitness) costs 487,500 (cited, figures stated for 41.78.16) (both)
• The starting-level XP boost is permanent: a skill you start at level 0 earns only 25% XP for the whole run, while starting levels 1, 2 and 3+ earn 100%, 133% and 166% — a level-1 start is roughly four times the XP rate of a level-0 start (cited) (both)
• Strength and Fitness are exempt from the starting-level boost system entirely (cited) (both)
• Skill books multiply XP in two-level bands — ×3 (levels 1–2), ×5 (3–4), ×8 (5–6), ×12 (7–8), ×16 (9–10) — and reading the right volume before grinding is the single biggest levelling lever (cited) (both)
• B41 only has skill books for crafting and survivalist skills; the B42-era book roster covers 24 skills, including first-ever books for Aiming, Reloading, Long Blade and Maintenance (cited) (B42)
• B42 adds nine genuinely new skills and renames three: Farming→Agriculture, Metalworking→Welding, Sprinting→Running (the internal IDs keep the old names) (cited) (B42)
• Brewing is a new B42 crafting system, not a skill — no Brewing skill exists in the cited roster (cited) (B42)
• The character-creation screen reportedly displays wrong boost percentages (+75/+100/+125 instead of the real 100/133/166) (community, unverified)
• Sandbox options include an XP Multiplier (0.001–1000, default 1) and a separate toggle for whether it touches passive skills, off by default (cited, B41-versioned page)

Purpose

This document answers the questions a player asks the moment they open the skills panel: how much XP does the next level actually need, why does my carpentry crawl while my friend's flies, which books should I read before I grind, what did Build 42 do to the skill list, and can I tune XP rates in sandbox? It exists so that levelling decisions — at character creation and mid-run — can be made from numbers rather than folklore.

Scope

Covered: the complete skill roster for B41.78 and B42.20-era pages, as build-tagged tables; per-level XP requirements including the passive Strength/Fitness scale; the permanent starting-level XP boost multipliers and their exceptions; skill-book mechanics, volume bands and per-build book coverage; how occupations and traits feed starting levels, at overview depth only; B42's new crafting and animal skills and the three renames; and sandbox XP options at overview level.

Not covered: per-occupation and per-trait tables (see players-traits-occupations), per-skill levelling routes and recipe unlocks (see players-crafting-chains and players-animals-husbandry), combat damage math beyond what defines a skill's effect, and multiplayer server XP configuration (Admins track). Spoiler-aware: no loot locations or story content appear here.

Definitions

• XP (experience points) — the per-skill points earned by performing that skill's activity; accumulating enough XP raises the skill level [4] [5].
• Regular skill — any skill outside the passive category; all share one XP-requirement scale [5].
• Passive skill — Strength or Fitness, the two-skill category with a far larger XP scale and special boost rules [5].
• XP boost (starting-level boost) — the permanent XP-rate multiplier a skill receives based on the level it had when the character was created [5] [7].
• Skill book — a readable item granting a temporary XP multiplier for one skill across a specific two-level band [6].
• Skill ID — the internal name a skill carries in game data, which several renamed B42 skills keep from their old display names [9] [10] [11].

Build Applicability

Build	Applies	Verified against	Notes
B41 (legacy41)	Yes	41.78.16	XP tables, boost multipliers and the 26-skill roster cited from a pzwiki revision explicitly versioned 41.78.16 [5]
B42 (stable)	Yes	42.20; patch notes re-read through 42.21	Roster and mechanics cited from pzwiki revisions versioned 42.3.1–42.19.0; the 42.20-specific fact is the skill-book XP fix in the release notes, and 42.21 adds only small fix notes (see Reference) [1] [4] [6] [7] [19] [20] [21]

The Skill page revision used for B42 facts still carries an editors' banner stating its categorisation is Build 41-based, and its XP table is labelled for 41.78.16 even on the B42-era revision — no independently verified B42 XP table has been published [4]. Treat every number here as "documented for 41.78, believed unchanged on 42.20" unless tagged otherwise.

Revision 0.2.0 (2026-10-07) re-read the 42.20.1, 42.20.2, 42.20.3 and 42.20.4 hotfix notes [15] [16] [17] [18], the 42.21 unstable and stable announcements [19] [20] and the abridged ("selected") TIS forum 42.21 changelist [21]. The four 42.20.x hotfix notes cover multiplayer, memory, security and mod-tooling fixes and list no skill, XP-requirement, multiplier or roster changes [15] [16] [17] [18]. Statements not named as 42.21-affected are carried forward from 42.20 and the cited pzwiki revisions with no contradicting change found in those notes; this is a patch-notes review, not an in-game re-test [21].

Reference

Levelling: from XP to skill levels

Every skill runs from level 0 to level 10, and the skills panel (press L, or open the health panel and pick the skills tab) shows current levels, with a hover tooltip revealing the XP still needed [4] [5]. XP arrives from performing the matching activity — sawing logs for carpentry, landing shots for aiming, casting a line for fishing — and each successive level demands more XP than the one before [4] [5].

Requirements are per-level, not running totals: the game asks for the level-4 chunk on its own after you have paid for levels 1–3 [5]. The table below restates the wiki's per-level figures (stated for build 41.78.16) alongside the cumulative cost, which this document computed by summation [4] [5]:

Level reached	Regular skill XP	Regular cumulative	Passive skill XP	Passive cumulative
1	75	75	1,500	1,500
2	150	225	3,000	4,500
3	300	525	6,000	10,500
4	750	1,275	9,000	19,500
5	1,500	2,775	18,000	37,500
6	3,000	5,775	30,000	67,500
7	4,500	10,275	60,000	127,500
8	6,000	16,275	90,000	217,500
9	7,500	23,775	120,000	337,500
10	9,000	32,775	150,000	487,500

The passive category — Strength and Fitness only — is the outlier by design: its level 1 alone costs twenty times a regular skill's level 1 (1,500 vs 75 XP), and mastery costs roughly fifteen times as much overall [5]. The same figures appear unchanged on the B42-era revision of the page, still labelled as 41.78.16 values [4].

The starting-level XP boost

The occupation and traits picked at character creation set each skill's initial level, and that initial level locks in a permanent XP-rate multiplier for the skill [5] [7] [8]. Both the B41 page revision and the B42-era Trait and Occupation revisions document the same actual rates [5] [7] [8]:

Starting level	Actual XP earned	Rate relative to a level-0 skill
0	25%	×1
1	100%	×4
2	133%	×5.32
3 or higher	166%	×6.64

In other words, a skill you never invested in at creation earns a quarter-rate trickle forever, while one point at creation quadruples its lifetime XP rate [5] [7]. The skills panel encodes the tier in the colour of the skill's name — gold for the top boost, then white, light grey, and dark grey for an unboosted skill [5].

Documented exceptions [4] [5]:

• Strength and Fitness sit outside the boost system altogether — their XP rate is identical whatever level you start them at [5].
• The Running skill (Sprinting on B41) uses its own ladder: 100%, 125%, 133% and 166% for starting levels 0, 1, 2 and 3+, so it never suffers the 25% penalty [4] [5].
• Aiming and Reloading take a flat ×0.37037 hit to XP gain once the character reaches level 5 in the respective skill [4] [5].

The percentages the creation screen displays are reportedly different from these actual rates — that discrepancy is quarantined as Claim 1 below.

Skill books: the two-level multiplier bands

Skill books are single-use readables that multiply XP earned in one skill, but only while the character is inside the volume's two-level band [6]. Five volumes exist per book-supported skill, each unlocking a successive two-level band from 1–2 (Volume I) up to 9–10 (Volume V) [6]. A volume cannot be opened below its band ("Skill level too low to read" appears in red), while reading one above your band wastes it — the character gains no boost [6]. The multiplier builds as you read: every 10% of pages completed grants 10% of the volume's maximum, sub-1.0 intermediate values are ignored, and the boost expires once the band's top level is reached [5] [6]. Boosts for several different skills can run at the same time, and active ones are marked by animated arrows in the skills panel, with the exact multiplier on hover [5] [6].

Volume	Band (levels)	Max multiplier	Pages	Band XP at full multiplier (regular skill)
I	1–2	×3	220	75 instead of 225
II	3–4	×5	260	210 instead of 1,050
III	5–6	×8	300	562.5 instead of 4,500
IV	7–8	×12	340	875 instead of 10,500
V	9–10	×16	380	1,031.25 instead of 16,500

Multiplier and page figures are the wiki's standard values (it notes multipliers can vary by topic); the final column is this document's arithmetic combining the band multiplier with the XP table above [5] [6]. Higher volumes have more pages and take proportionally longer to read [6].

Coverage differs sharply by build. On B41, only the crafting and survivalist categories have books at all — eleven skills in total under that revision's grouping (B41) [5]. The B42-era Skill book page lists books for 24 skills: the whole crafting family (including all seven new B42 crafting skills), Agriculture, Animal Care, Butchering, Tracking, the survivalist set, and — new territory for the series — Aiming, Reloading, Long Blade and Maintenance (B42) [6]. No books exist for passive or agility skills on either build, nor for melee skills other than Long Blade and Maintenance (B42) [6]. Book item IDs preserve renamed skills' old identities — Agriculture volumes are Base.BookFarming1 through Base.BookFarming5 (B42) [6].

One 42.20-stable primary fact belongs here: the release patch notes fix the XP boost from skill books "not being calculated properly in some cases", so book behaviour on 42.20 differs from late-unstable builds in unspecified edge cases (B42) [1].

The 42.21 stable release (2026-09-28) adds three small fix notes in this area (B42) [20]. The forum changelist's multiplayer list records that Nimble XP was not being granted while in combat stance in multiplayer, now fixed [21]. Its split-screen list records that read-book status and XP boosts were being shared incorrectly between local players, now fixed, and the unstable announcement repeats that point [19] [21]. Its singleplayer list records a fix for PerkLog.txt not recording perk changes [21]. The changelist as retrieved lists no change to XP requirements, multipliers or the skill roster; it is abridged, so that is an absence in a partial list, not a confirmation [21].

Where starting levels come from: occupations and traits

Occupations grant the larger starting-level packages, positive traits add smaller ones, and both feed the boost table above — which is why the wiki frames creation choices as permanent XP-rate decisions [5] [7] [8]. Two traits modify XP rates globally rather than via starting levels: Fast Learner raises a skill's XP rate to 130% and Slow Learner lowers it to 70% [11]. The full per-occupation and per-trait rosters, point costs and B41/B42 roster differences live in players-traits-occupations; this document deliberately stops at the mechanism.

The skill roster, per build

Build 41.78.16 has 26 skills in six categories (B41) [5]:

Category (B41)	Skills	Count
Passive	Fitness, Strength	2
Agility	Lightfooted, Nimble, Sneaking, Sprinting	4
Combat	Axe, Long Blunt, Short Blunt, Long Blade, Short Blade, Spear, Maintenance	7
Crafting	Carpentry, Cooking, Farming, First Aid, Electrical, Metalworking, Mechanics, Tailoring	8
Firearm	Aiming, Reloading	2
Survivalist	Fishing, Foraging, Trapping	3

The B42-era revision of the same page lists 35 skills across seven groups — while carrying an editors' banner that the categorisation is still Build 41-based, so the shipped 42.20 grouping may present differently (B42) [4]:

Group (B42)	Skills	Count
Passive	Fitness, Strength	2
Agility	Lightfooted, Nimble, Running, Sneaking	4
Combat	Axe, Long Blunt, Short Blunt, Long Blade, Short Blade, Spear, Maintenance	7
Crafting	Carpentry, Cooking, Electrical, Mechanics, Tailoring — joined by Blacksmithing, Carving, Glassmaking, Knapping, Masonry, Pottery, Welding	12
Farming	Agriculture, Animal Care, Butchering	3
Firearm	Aiming, Reloading	2
Survivalist	First Aid, Fishing, Foraging, Tracking, Trapping	5

Note the moves as well as the additions: First Aid sits under Crafting on B41 but Survivalist on the B42-era page, and the farming skills gained a group of their own [4] [5].

B42's new skills and renames

The seven new crafting skills back Build 42's expanded tech tree — announced around the unstable launch as new crafting systems including pottery, blacksmithing and stone working [2] [13]. In one line each, per the cited revision [4]:

• Knapping — shapes flint and stone into primitive tool components, up to a large stone axe head at higher levels [4] [14].
• Masonry — improves brick and stone construction and shares the top-end stone recipes with Knapping [4].
• Carving — turns wood and bone into simple tools, handles, hooks and basic weapons using a blade [4].
• Blacksmithing — forges metal tools, armour and weapons at dedicated workstations, rivalling looted equivalents at high level [4].
• Welding — builds and repairs metal structures and vehicle parts; the direct successor to B41's Metalworking, and its internal Skill ID is still MetalWelding [4] [5] [10].
• Pottery — produces clay goods such as bricks and ceramic vessels at a pottery bench or wheel [4].
• Glassmaking — melts sand or broken glass into workable glass for recipes [4].

The animal economy adds three more: Animal Care (reading animal condition and improving yields such as milk and wool), Butchering (meat quality when processing carcasses), and Tracking (identifying and following wild-animal signs in search mode) [4]. Tracking is also the one skill of the ten to appear by name in a pre-release Thursdoid, which describes following animals' droppings and broken twigs [3]. The 42.20 release notes further increase meat cuts from large animals on the butcher hook, touching Butchering's economy [1]. Deeper treatments live in players-crafting-chains and players-animals-husbandry.

Three renames, all keeping their internal IDs: B41's Farming is B42's Agriculture (Skill ID Farming) — the wiki records it was renamed in Build 42 [4] [5] [9]; Metalworking became Welding (MetalWelding) [5] [10]; Sprinting became Running (Sprinting) [5] [11].

One deliberate clarification: Brewing is not a skill. The Build 42 overview lists brewing among the new crafting systems alongside pottery, blacksmithing, stone working and weapon crafting, but no Brewing skill appears in the cited roster and no Brewing skill page exists on the wiki [4] [13].

Sandbox XP options (overview)

The Custom Sandbox page documents an XP Multiplier option scaling all task XP, with range 0.001–1000 and default 1, plus a companion toggle, XP Multiplier Affects Passive Skills, default off, which decides whether Strength and Fitness ride the multiplier [12]. That page revision is versioned against 41.78.19, so treat the exact bounds as B41-verified and B42-probable (B41) [12]. During the unstable cycle The Indie Stone listed "XP gain adjustments" among areas of active tuning, so unstable-era XP feel is not a reliable guide to 42.20 [2]. Server-side XP configuration is Admins-track territory.

B41 vs B42 Delta

Area	Build 41.78 (B41)	Build 42 (B42)
Roster size	26 skills, six categories [5]	35 skills, seven listed groups (categorisation banner pending) [4]
New skills	—	Blacksmithing, Carving, Glassmaking, Knapping, Masonry, Pottery, Animal Care, Butchering, Tracking [4]
Renames	Farming, Metalworking, Sprinting [5]	Agriculture (Farming), Welding (MetalWelding), Running (Sprinting) [4] [9] [10] [11]
Category moves	First Aid and Farming under Crafting [5]	First Aid under Survivalist; farming skills in their own Farming group [4]
XP tables	Stated for 41.78.16 [5]	Same table republished, still labelled 41.78.16 — no verified B42 table [4]
Starting-level boost	25/100/133/166%, Sprinting exception [5]	Same values documented; exception now under Running [4] [7] [8]
Skill books	Crafting + survivalist categories only (11 skills) [5]	24 skills incl. Aiming, Reloading, Long Blade, Maintenance; book XP-boost bug fixed in 42.20 [1] [6]; split-screen sharing of book status and XP boosts fixed in 42.21 [19] [21]
Brewing	—	New crafting system, not a skill [13]
Sandbox XP options	XP Multiplier + passive toggle documented on a 41.78.19-versioned page [12]	Presence expected but bounds not re-verified; unstable cycle included XP tuning [2] [12]

Summed up: the mathematics of levelling is documented as unchanged between builds, but the surface it applies to grew by a third — nine new skills, three renames, a regrouped panel, and skill books extending into combat and firearms for the first time [1] [4] [5] [6].

Practical Guidance

• Buy your XP rate at creation, not later. The jump from 25% to 100% XP for one starting level is the best-value purchase in the game — put creation points into the two or three skills you actually intend to grind, and treat everything at level 0 as a quarter-speed hobby.
• Match the book to the band before you grind. Grinding levels 5–6 without Volume III means paying 4,500 XP at full price when 562.5 would do. The habit that separates efficient survivors: find the book, read it fully, then grind.
• Don't burn a volume early. Reading above your band grants nothing, and books are single-use. Check the skills panel band first.
• Expect Strength and Fitness to be marathon projects. At twenty times the level-1 cost of a regular skill and no starting-level boost, the passive pair rewards routine (regular exercise, encumbered living) rather than bursts — and the sandbox passive-XP toggle is off by default, so a raised XP Multiplier won't speed them up unless you flip it [12].
• On B42, plan around the new families. Knapping and Carving are the low-tech entry points, Masonry and Blacksmithing the high-end payoffs — if you intend a crafting run, spread starting levels accordingly and see players-crafting-chains for routes.
• Returning from B41? Look for your old skills under new names — Agriculture, Welding, Running — before concluding they were removed; the underlying IDs are unchanged [9] [10] [11].
• Aiming and Reloading now have books on B42 — worth shelf-checking before a firearms-heavy phase, especially given their documented post-level-5 XP slowdown [4] [6].

Common Pitfalls & Troubleshooting

• "My unlevelled skills barely move." Working as designed: level-0 skills earn 25% XP [5] [7]. The fix is at character creation, not in play.
• "The creation screen said +75%, this document says 100%." The displayed percentages are community-reported as incorrect — see Claim 1; the actual rates in the table above are the wiki's tested values [7] [8].
• "I read the book but got no boost." Either you were above the volume's band (the read is wasted) or below it (the game refuses the read); and on pre-42.20 builds, a now-fixed calculation bug could also under-apply book boosts [1] [6].
• "Sandbox XP Multiplier didn't touch Strength/Fitness." The passive pair has its own toggle, default off [12].
• "Where did Farming/Metalworking/Sprinting go on B42?" Renamed, not removed: Agriculture, Welding, Running [4] [9] [10] [11].
• "Where's the Brewing skill?" There isn't one — brewing is a crafting system without an attached skill in the cited roster [4] [13].
• Trusting unstable-era XP feel on 42.20. XP gain was explicitly on the tuning list during unstable, and 42.20 changed skill-book behaviour; re-test before importing habits [1] [2].

Community Notes & Unverified Claims

Claim 1 — The character-creation screen displays the wrong XP-boost percentages

• Claim: The boost values shown in-game for starting levels 1, 2 and 3 read +75%, +100% and +125%, while the real experience rates are 100%, 133% and 166%; pzwiki documents this identically on its Trait and Occupation pages, stamped as present on version 42.13.1, and its B41-era Skill page carried the same displayed-versus-actual split.
• Why unverified: No Indie Stone patch note or dev post acknowledges the display bug, the wiki notes it was never reported on the official forums, and the 42.13.1 stamp predates 42.20 — it may have been silently fixed at stable.
• Confidence: Medium. Consistently documented across multiple independently maintained wiki pages on both builds' revisions, but resting entirely on community testing.

Claim 2 — Strength/Fitness starting boosts are displayed even when disabled in sandbox

• Claim: Per the pzwiki Trait page, Build 41.78.16 shows a starting boost for Strength and Fitness in the UI even when the relevant sandbox behaviour disables it.
• Why unverified: The wiki itself marks the statement with a "verify" flag, no primary source exists, and the exact sandbox setting involved is not named.
• Confidence: Low. Single-sourced from a wiki sentence that the wiki's own editors have flagged for verification.

Claim 3 — Build 42 uses the same XP-requirement table as 41.78.16

• Claim: Community guides and the wiki's B42-era Skill revision treat the 41.78.16 XP table (75→9,000 regular, 1,500→150,000 passive) as still accurate for Build 42.
• Why unverified: The B42-era page simply republishes the table with its B41 label rather than asserting re-verification, and The Indie Stone listed XP gain among unstable-cycle tuning targets — gain rates changing would not change requirements, but no primary source confirms the requirement table either way for 42.20.
• Confidence: Medium. No contradicting report has surfaced across the unstable cycle, but positive confirmation on 42.20 is absent.

Risks & Caveats

• Nothing here is 42.20-re-verified except the patch-note facts, and 42.21 was checked against patch notes only. The Skill page is versioned 42.3.1 with an outdated-categorisation banner, Skill book 42.13.2, Occupation 42.18.0, Trait 42.19.0, Running 42.18.0, and Custom Sandbox 41.78.19 [4] [6] [7] [8] [11] [12]. That spread is the core reason for the Medium rating.
• The 42.20 skill-book XP fix has an unspecified scope ("in some cases"), and 42.21 later fixed further XP-adjacent issues (split-screen boost sharing, Nimble XP in multiplayer combat stance), so adjacent behaviour has already moved once after 42.20 [1] [19] [21].
• The B42 grouping table may not match the in-game panel given the wiki's own banner; the membership of the roster is better attested than its presentation [4].
• Cumulative XP columns and the book-band "effective XP" column are this document's arithmetic over cited per-level figures, not independently published numbers.
• Rename statements combine two revisions plus internal IDs; only Farming→Agriculture is stated outright by the wiki as a Build 42 rename [9]. Welding and Running are inferred from roster comparison plus preserved Skill IDs [5] [10] [11].
• Skill-book multipliers "can vary between each topic" per the wiki's own caption — the ×3/×5/×8/×12/×16 ladder is the standard case, not a guarantee for every book [6].

Verification Steps

1. XP table (42.20): in-game, hover a level-0 regular skill in the skills panel (L) and confirm 75 XP to level 1; hover Strength and confirm 1,500.
2. Starting-level boost: create a character with one skill at level 1, note XP gained per action versus the same action on a level-0 skill; a 4:1 ratio confirms the 100%/25% split.
3. Display bug (Claim 1): at character creation on 42.20, record the boost percentages shown for starting levels 1–3 and compare with 100/133/166.
4. Book bands: attempt to read a Volume II at skill level 1 (expect refusal) and a Volume I at level 3 (expect no boost).
5. Roster: open the 42.20 skills panel and tick off the 35-skill B42 table above; note the panel's actual grouping against the wiki's B41-based categorisation.
6. Sandbox options: open Custom Sandbox on 42.20, locate XP Multiplier and the passive-skills toggle, and record their bounds and defaults against the 41.78.19-versioned figures.
7. Sources: each pzwiki citation below pins an exact oldid — diff against the live page for post-42.20 corrections.

Open Questions

• Does 42.20 or 42.21 still display the wrong starting-boost percentages (Claim 1)? The 42.21 changelist as retrieved does not mention it [21]; one character-creation screenshot resolves it.
• What is the shipped 42.20 skill-panel grouping, given the wiki's outdated-categorisation banner [4]?
• Which "cases" did the 42.20 skill-book XP fix cover, and did effective multipliers change [1]?
• Are the XP requirements per level identical on 42.20 (Claim 3)? A tooltip sweep across one regular and one passive skill resolves it.
• Do the Custom Sandbox XP options carry the same bounds and defaults on B42 [12]?
• Do any B42 books deviate from the standard multiplier ladder, and by how much [6]?

References

Primary Sources

• [1] The Indie Stone — Build 42.20.0 Stable Released (Steam announcement, 2026-07-29; retrieved via Steam news API, ISteamNews app 108600). https://steamcommunity.com/games/108600/announcements/detail/1839676055882259. Accessed 2026-07-30.
• [2] The Indie Stone — Build 42 Unstable Out Now (Steam announcement, 2024-12-17). https://steamcommunity.com/games/108600/announcements/detail/1785774543698069. Accessed 2026-07-30.
• [3] The Indie Stone — WhatZ Next (Thursdoid, Steam announcement, 2024-11-28). https://steamcommunity.com/games/108600/announcements/detail/1784506359022970. Accessed 2026-07-30.
• [15] The Indie Stone — 42.20.1 STABLE Hotfix Released (Steam announcement, 2026-08-05). https://steamcommunity.com/games/108600/announcements/detail/1840310314338766. Accessed 2026-10-07.
• [16] The Indie Stone — 42.20.2 STABLE Hotfix Released (Steam announcement, 2026-08-05). https://steamcommunity.com/games/108600/announcements/detail/1840310314339441. Accessed 2026-10-07.
• [17] The Indie Stone — 42.20.3 STABLE Hotfix Released (Steam announcement, 2026-08-17). https://steamcommunity.com/games/108600/announcements/detail/1840944183785895. Accessed 2026-10-07.
• [18] The Indie Stone — 42.20.4 STABLE & 42.19.2 UNSTABLE & 41.78.21 LEGACY Hotfixes Released (Steam announcement, 2026-08-26). https://steamcommunity.com/games/108600/announcements/detail/1842212951296601. Accessed 2026-10-07.
• [19] The Indie Stone — Re-population of the Dead: Build 42.21 Unstable Released (Steam announcement, 2026-09-23). https://steamcommunity.com/games/108600/announcements/detail/1844751498218925. Accessed 2026-10-07.
• [20] The Indie Stone — Build 42.21 Stable Released (Steam announcement, 2026-09-28). https://steamcommunity.com/games/108600/announcements/detail/1844751498231307. Accessed 2026-10-07.
• [21] The Indie Stone — 42.21 Patch Notes (TIS forum topic 101693, first post by Rockjaw, 2026-09-23; retrieved abridged, "selected" lists only). https://theindiestone.com/forums/topic/101693-4221-patch-notes/. Accessed 2026-10-07.

Fact-Only Sources (no prose reuse) — pzwiki (CC BY-NC-SA 3.0): cite URL + revision id; facts only, never prose.

• [4] PZwiki — Skill (revision 1436755; page versioned against 42.3.1, carries an outdated-categorisation banner; confirmed still the latest revision on 2026-07-30). https://pzwiki.net/w/index.php?title=Skill&oldid=1436755. Accessed 2026-07-30. Fact-only source.
• [5] PZwiki — Skill (revision 663165, 2024-12-14; page versioned against 41.78.16 — the pre-Build 42 revision, used for all B41 facts). https://pzwiki.net/w/index.php?title=Skill&oldid=663165. Accessed 2026-07-30. Fact-only source.
• [6] PZwiki — Skill book (revision 1317189; page versioned against 42.13.2). https://pzwiki.net/w/index.php?title=Skill_book&oldid=1317189. Accessed 2026-07-30. Fact-only source.
• [7] PZwiki — Trait (revision 1442751; page versioned against 42.19.0). https://pzwiki.net/w/index.php?title=Trait&oldid=1442751. Accessed 2026-07-30. Fact-only source.
• [8] PZwiki — Occupation (revision 1391359; page versioned against 42.18.0). https://pzwiki.net/w/index.php?title=Occupation&oldid=1391359. Accessed 2026-07-30. Fact-only source.
• [9] PZwiki — Agriculture (revision 1439053; records the Build 42 rename from Farming and the Farming Skill ID). https://pzwiki.net/w/index.php?title=Agriculture&oldid=1439053. Accessed 2026-07-30. Fact-only source.
• [10] PZwiki — Welding (revision 1436247; records the MetalWelding Skill ID). https://pzwiki.net/w/index.php?title=Welding&oldid=1436247. Accessed 2026-07-30. Fact-only source.
• [11] PZwiki — Running (revision 1435413; page versioned against 42.18.0; records the Sprinting Skill ID and Fast/Slow Learner rates). https://pzwiki.net/w/index.php?title=Running&oldid=1435413. Accessed 2026-07-30. Fact-only source.
• [12] PZwiki — Custom Sandbox (revision 1442995; page versioned against 41.78.19). https://pzwiki.net/w/index.php?title=Custom_Sandbox&oldid=1442995. Accessed 2026-07-30. Fact-only source.
• [13] PZwiki — Build 42 (revision 1443663; lists brewing among new crafting systems). https://pzwiki.net/w/index.php?title=Build_42&oldid=1443663. Accessed 2026-07-30. Fact-only source.
• [14] PZwiki — Knapping (revision 1439145; records the FlintKnapping Skill ID). https://pzwiki.net/w/index.php?title=Knapping&oldid=1439145. Accessed 2026-07-30. Fact-only source.

Secondary & Corroborating — none cited.

Community & Creator — none cited.

Further Reading

Further Reading

• The Steam news API feed used to verify announcement primaries: https://api.steampowered.com/ISteamNews/GetNewsForApp/v2/?appid=108600&count=25
• The Indie Stone's Build 42 feature overview, linked from the 42.20 release notes: https://projectzomboid.com/blog/features-overview-build-42-20/ (bot-blocks automated checkers; verify in-browser).
• pzwiki's per-skill pages (Carpentry, Blacksmithing, Foraging, …) for levelling routes beyond this document's scope.

Related Documents

• players-foundation — the Players-track overview this document deepens.
• players-traits-occupations — full occupation and trait rosters feeding the starting-level boost.
• players-crafting-chains — how the new B42 crafting skills chain together in practice.
• players-animals-husbandry — Animal Care, Butchering and Tracking in the animal economy.
• meta-style-guide — the style rules this document conforms to.

Revision History

Version	Date	Author	Change	Approved By
0.1.0	2026-07-30	KB Pipeline (virtual agent)	Initial draft.	—
0.2.0	2026-10-07	KB Pipeline (revision worker)	42.21 re-baseline against the 42.20.1–42.20.4 hotfix notes, the 42.21 unstable and stable Steam posts and the abridged TIS forum 42.21 changelist: Nimble XP combat-stance (MP) fix, split-screen book-status/XP-boost fix and PerkLog.txt fix recorded; Build Applicability, Delta, Risks and Open Questions updated; no XP numbers changed. Rebase is a patch-notes review, not an in-game re-test.	—
1.0.0	2026-10-08	Orchestrator (KB Pipeline)	Approved and frozen — release kb-release-2026.10.08 (42.21 re-baseline; validated against 42.21 and 41.78.21, Umbrella 42.21.0 @ 13d01f9). Content is the reviewed 0.2.0 text.	Project owner (user instruction 2026-10-08)