Mod

A mod is a modification of the content of a video game in terms of gameplay or simply aesthetics, such as graphical improvements, alterations, additions, and more. In, mods are fully supported and can be accessed in the content menu. Mods can be "installed" through the Steam Workshop by simply adding a mod to the user's favorites.

While mods are fully supported in Cities: Skylines, mods are prone to break easily after every update, requiring the creator of the mod to update the mod to the latest version if broken.

Mods will disable achievements, including saves that were not started with mods. By adding mods to a save, the save file will no longer be allowed to collect achievements, even when the mods are disabled afterward.

Creating content mods
Content mods can be created through three different types of content editors: map editor, asset editor, and theme editor.


 * Map editor
 * The map editor allows players to create custom maps using a variety of tools for landscaping. The map editor is capable of defaulting to a specific theme, such as boreal or temperate.


 * Asset editor
 * The asset editor allows players to create custom props and buildings that can be added to cities to beautify and create a unique environment. Assets can come from building custom roads and highways to uniquely styled buildings.


 * Theme editor
 * The theme editor allows players to create a custom theme style. The terrain, water, and atmosphere textures can be adjusted to fit anything the player desires.

Modding API
Modders can also alter the gameplay of Cities: Skylines. This allows for new styles of play, such as adjusting traffic simulations to road anarchy.

Pre-added mods
Mods can be pre-added to the game by Paradox Interactive or Colossal Order themselves. These mods are fully supported and should not be game-breaking after each update.
 * Hard mode: difficulty of the game increases
 * Unlimited money: infinite supply of money
 * Unlock all milestones: all milestones achieved, regardless of the size and population of the city