3: Conquests - Sid Meier's Civilization

: A new unit type that can appear when a civilization is the first to research a technology. They can be used to "rush" any city improvement or Great Wonder, though their secondary ability to trigger a "Scientific Golden Age" is famously bugged in the retail version.

: Two new tiers were added above Deity: Demigod and Sid . On "Sid" difficulty, the AI receives massive bonuses, such as starting with extra Settlers and having significantly lower production costs. Sid Meier's Civilization 3: Conquests

: Added the Feudalism and Fascism government types to provide more mid-to-late game strategic options. The "Conquests" Scenarios : A new unit type that can appear

The expansion introduced several mechanics that fundamentally altered the Civilization III experience: On "Sid" difficulty, the AI receives massive bonuses,

Analysis of Sid Meier’s Civilization III: Conquests Sid Meier’s Civilization III: Conquests , released in 2003, is the second and final expansion for Civilization III . It is widely regarded by the community as the definitive version of the game, introducing substantial content that shifted the focus from broad empire-building to specialized, objective-driven scenarios. Core Gameplay Enhancements

The centerpiece of the expansion is its nine professionally designed scenarios, which use custom rulesets to recreate specific historical eras. Civilization III: Frequently Asked Questions - CivFanatics