Best free "real-time strategy" games

GAME GENRE – A real-time strategy game (RTS) is a type of video game in which players manage units and resources in a dynamic, real-time environment. RTS games emphasize strategic planning, decision-making, and multitasking. Players typically control armies, civilizations, or factions, aiming to defeat opponents through military, economic, and sometimes diplomatic means.
Popular examples of RTS games include StarCraft, Age of Empires, Command & Conquer, Warcraft, and the Total War series. While settings, objectives, and complexity vary, all RTS games share the core elements of real-time strategic gameplay.