In Civilization VII (Civ 7), Codices are a unique type of Great Work introduced during the Antiquity Age, focusing on scientific and historical knowledge. Here's an in-depth look at how Codices function within the game:
What Are Codices?
•Definition: A Codex (plural: Codices) is a special Great Work that players can collect. Unlike artworks or music, Codices are centered around science, providing boosts to scientific output and contributing to the Science Legacy Path.
•Purpose: They are crucial for advancing scientific research and are part of the game's new mechanics aimed at rewarding early game exploration and technological advancement.
Acquiring Codices:
Codices can be acquired through various means:
•Technology Mastery: Mastering technologies like Writing, The Wheel, Navigation, Engineering, Military Training, and Mathematics grants you Codices. Mathematics Mastery specifically rewards two Codices.
•Civics: Advancing through the civics tree can also yield Codices. For instance, completing the Literacy civic provides one Codex.
•Wonders: Building the Nalanda Wonder gives you one Codex and adds two slots for Codices.
•Narrative Events: Random narrative events might offer Codices as rewards, depending on the choices made by the player.
•City-State Influence: Becoming the Suzerain of a Scientific City-State can sometimes grant a Codex.
•Great People: Specific civilizations might have Great People who grant Codices upon being recruited.
Displaying Codices:
•Slots: Codices need to be placed in buildings with Great Work slots to provide their benefits:
•Palace: Comes with one slot.
•Library: Offers two slots for Codices.
•Academy: Has three slots.
•Nalanda Wonder: Adds two more slots.
•Benefits: Displaying Codices increases your Science output, thereby accelerating your progress through the Technology Tree.
•Science Legacy Path: Collecting and displaying 10 Codices during the Antiquity Age completes the Science Legacy Path, leading to the Great Library Golden Age in the Exploration Age. This age bonus allows Academies to retain their yields and adjacency bonuses, providing a significant early advantage.
Strategic Considerations: 
•Early Game Focus: If your strategy involves a Science Victory or rapid technological advancement, gathering Codices should be a priority.
•Slot Management: With only a limited number of Codex slots early in the game, strategic placement is crucial. Losing a city with displayed Codices can significantly impact your science output.
•Balancing Growth: While collecting Codices, ensure your cities are growing and producing enough to support the buildings needed for Codex slots.
•Narrative Engagement: Engaging with narrative events can sometimes provide unexpected Codices, so don't overlook these opportunities.
Challenges:
•Limited Slots: If you run out of slots for Codices, they won't contribute to your science output until you expand your display capabilities.
•Loss of Codices: If a city containing Codices is lost or a building with displayed Codices is destroyed, you lose access to those science bonuses until you recover or rebuild.
Community Feedback:
Players have expressed on platforms like Reddit and forums that the challenge of collecting all 10 Codices in one age can be significant, especially if the game doesn't provide enough opportunities through technology or civics mastery.
Strategies shared include focusing on city-state quests, choosing the right civics, and prioritizing wonder construction like Nalanda for additional Codex slots.
In summary, Codices in Civilization VII are pivotal for players aiming for scientific dominance or those who want to leverage early game advantages. They require strategic planning to maximize their benefits while navigating the game's challenges.
