Ruleset library / know what changes
Choose the kind of difference you want.
Unciv makes modding part of the game’s identity. Before starting a different setup, decide whether you want more content within familiar rules, a new collection of rules or another way to see the same game. Those choices lead to different kinds of mods.
Extension
Adds to a base ruleset. A new civilisation is a useful example: you can explore a different starting package without replacing the entire structure of the game.
Base ruleset
Replaces the core definitions, potentially including technologies, units, policies and nations. Read its description as the introduction to a different game, and expect familiar names or assumptions to need checking.
Audiovisual & maps
Ruleset-agnostic content changes other parts of the experience. Tilesets, interface skins, fonts and map mods belong here; their purpose differs from adding another nation or replacing the technology tree.
Build a setup you can understand
Open Mods from the main menu to browse the available content. Read the mod’s description, then check the ruleset and extension choices when creating a game. Begin with a combination you can explain; adding several unfamiliar changes at once makes it harder to understand which one caused a new behaviour.
Choose mods that support the ruleset you plan to play. For a new combination, begin with a separate game so you can explore the changes without interrupting a favourite campaign.