what engine is cs2 on

Counter-Strike 2, also known as CS2, was built using the Source 2 engine. The Source 2 engine is a video game engine developed by Valve and was announced in 2015 as the successor to the original Source engine. The engine has been used in several Valve games, including Dota 2, Half-Life: Alyx, and Artifact. CS2 is a free replacement for CS:GO and includes updates to some of the games core mechanics, including improved smoke grenades and "sub-tick updates" that let servers know the exact instant that motion starts, a shot is fired, or a grenade is thrown. The game also has revamped maps, better visuals, UI enhancements, reworked audio, and more.