Stonework

_{Focus Areas · Design document §3}

Available from: Game Start

10 breakthroughs — CORE 3 · STANDARD 1 · UNCOMMON 3 · RARE 1 · UNIQUE 2 — Primitive – Ancient

Builds on: Fire (1) · Observation (1) · Philosophy and the Arts (1) · Trade (1)

Leads into: Fire (1) · Observation (1) · Mining (2) · Construction (3) · Seafaring (1) · Warfare (1) · Philosophy and the Arts (1) · Water Management (1) · Mechanics (1)

_{The numbers count prerequisite links between this focus and the other. How to read the tables.}

Overview

ID	Breakthrough	Tier	Era	Prerequisites
S01	Tool Knapping	CORE	Primitive	None
S02	Grinding & Polishing	STANDARD	Primitive	S01
S03	Quarrying	CORE	Ancient	S01
S04	Ore Identification	CORE	Primitive	S01
S05	Obsidian Working	UNCOMMON	Primitive	S01 + Volcanic region
S07	Flint Knapping Mastery	UNCOMMON	Primitive	S01
S08	Jade/Gemstone Working	UNCOMMON	Ancient	S02
S09	Geopolymer Concrete	RARE	Ancient	S03 + F02 (Kiln Construction)
S10	Obsidian Trade Empire	UNIQUE	Ancient	S05 (Obsidian Working) + TR01 + Volcanic region
S11	Megalithic Observatory	UNIQUE	Ancient	CU02 (Monumental Architecture — the megaliths) + O01 + Isolated start or Coastal start

Prerequisite map

flowchart LR
  n_S01["S01 Tool Knapping"]:::CORE
  n_S02["S02 Grinding #38; Polishing"]:::STANDARD
  n_S08["S08 Jade/Gemstone Working"]:::UNCOMMON
  n_S03["S03 Quarrying"]:::CORE
  n_S09["S09 Geopolymer Concrete"]:::RARE
  n_S04["S04 Ore Identification"]:::CORE
  n_S05["S05 Obsidian Working"]:::UNCOMMON
  n_S10["S10 Obsidian Trade Empire"]:::UNIQUE
  n_S07["S07 Flint Knapping Mastery"]:::UNCOMMON
  n_S11["S11 Megalithic Observatory"]:::UNIQUE
  n_S01 --> n_S02
  n_S01 --> n_S03
  n_S01 --> n_S04
  n_S01 --> n_S05
  n_S01 --> n_S07
  n_S02 --> n_S08
  n_S03 --> n_S09
  n_S05 --> n_S10
  classDef CORE fill:#dbeafe,stroke:#1d4ed8,color:#0b1b3b
  classDef STANDARD fill:#f1f5f9,stroke:#64748b,color:#0f172a
  classDef UNCOMMON fill:#dcfce7,stroke:#15803d,color:#052e16
  classDef RARE fill:#fef3c7,stroke:#b45309,color:#3b2005
  classDef UNIQUE fill:#fae8ff,stroke:#a21caf,color:#3b0a3f

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_{Prerequisites within this focus. Box colour is the tier (blue CORE, grey STANDARD, green UNCOMMON, amber RARE, purple UNIQUE); dotted arrows are alternatives (“or”); a line can pass behind another box, so follow it from its start. 3 of these 10 breakthroughs also need breakthroughs from other foci, which the overview above lists.}

Breakthroughs

S01 · Tool Knapping

• Tier: CORE · Era: Primitive
• Prerequisites: None
• Unlocks: Warrior, Scout (units); Remove Forest, Remove Jungle (improvements). Stone tools: the first weapons and the first clearing of land.
• Notes: Foundation.
• Leads to: S02 Grinding & Polishing, S03 Quarrying, S04 Ore Identification, S05 Obsidian Working, S07 Flint Knapping Mastery, SF02 Dugout Canoe, WA03 Archery, CU04 Musical Instruments, MC01 Wheel

S02 · Grinding & Polishing

• Tier: STANDARD · Era: Primitive
• Prerequisites: S01
• Unlocks: ⟨[-25]% construction time for [Quarry] improvements⟩ — polished stone cuts stone. Polished tools and decorative stonework.
• Notes: Neolithic revolution in tool quality.
• Leads to: S08 Jade/Gemstone Working

S03 · Quarrying

• Tier: CORE · Era: Ancient
• Prerequisites: S01
• Unlocks: Walls, Stone Works (and the Babylonian Walls of Babylon); Quarry (improvement); unlocks Construction focus.
• Leads to: S09 Geopolymer Concrete, CO02 Post and Lintel, CO03 Arch Construction, CO05 Corbel Arch/Vault, WM01 Canal Building

S04 · Ore Identification

• Tier: CORE · Era: Primitive
• Prerequisites: S01
• Unlocks: Reveals Copper, Gold Ore, Gems and Iron (their revealedBy — hidden until now); Mine (improvement); unlocks Mining focus. Suddenly you see where the wealth is buried.
• Notes: Exciting map reveal moment — suddenly you see where the wealth is buried.
• Leads to: F04 Smelting Discovery, O08 Geological Observation, MI05 Deep Shaft Mining, MI06B Volcanic Ash Processing

S05 · Obsidian Working

• Tier: UNCOMMON · Era: Primitive
• Prerequisites: S01 + Volcanic region
• Unlocks: Reveals Obsidianⁿ (new luxury resource, found on Volcanic tiles; improved by Mine); Obsidian Warriorⁿ [unit, Sword type; cost 45; mv 2; str 10; requires Obsidian]. Sharper than steel, and a luxury besides.
• Notes: Sharper than modern surgical steel.
• Leads to: S10 Obsidian Trade Empire

S07 · Flint Knapping Mastery

• Tier: UNCOMMON · Era: Primitive
• Prerequisites: S01
• Unlocks: ⟨[+10]% Strength <for [Ranged] units>⟩. Better points fly truer.

S08 · Jade/Gemstone Working

• Tier: UNCOMMON · Era: Ancient
• Prerequisites: S02
• Unlocks: Jewelerⁿ [95/1; +2 Gold; ⟨[+1 Gold] from [Gems] tiles [in this city]⟩; ⟨[+1 Gold] from [Silver] tiles [in this city]⟩; ⟨Provides [1] [Jewelry]⟩].

S09 · Geopolymer Concrete

• Tier: RARE · Era: Ancient
• Prerequisites: S03 + F02 (Kiln Construction)
• Unlocks: Geopolymer Worksⁿ [30/0; cityHealth +25; ⟨[-25]% maintenance cost for [All] buildings [in this city]⟩]. Buildings that shrug off siege and time — without the Roman Concrete path.
• Notes: Speculative: Egyptian/ancient concrete theories.

S10 · Obsidian Trade Empire

• Tier: UNIQUE · Era: Ancient
• Prerequisites: S05 (Obsidian Working) + TR01 + Volcanic region
• Unlocks: Obsidian Exchangeⁿ [replaces Market; 100/0; +3 Gold; Gold +25%; Merchant ×1; ⟨[+2 Gold] from [Obsidian] tiles [in this city]⟩]. Civ uniques: ⟨[+2 Gold] from [Volcanic] tiles [in all cities]⟩; ⟨[+1 Production] from [Obsidian] tiles [in all cities]⟩. Every vent you hold is a trade good.
• Notes: Mesoamerican obsidian trade networks spanned thousands of miles.

S11 · Megalithic Observatory

• Tier: UNIQUE · Era: Ancient
• Prerequisites: CU02 (Monumental Architecture — the megaliths) + O01 + Isolated start or Coastal start
• Unlocks: Standing Stonesⁿ [national wonder; 100/0; +3 Science, +2 Faith; +10% Insight to Observation and Mathematics]. Civ unique: ⟨[+1 Science] from all [World Wonder] buildings⟩ and ⟨[+1 Science] from all [Monument] buildings⟩ — every monument is an instrument.
• Notes: Stonehenge, Newgrange, Carnac.