In the early days of the GoldSrc engine, "ragdoll physics" as we know them today did not exist. When you killed an enemy in CS 1.6, the "kill effect" was dictated by pre-baked animations.
This plugin triggers visual and audio queues simultaneously. For example: cs 1.6 kill effect
Most modern CS 1.6 servers use AMX Mod X to add "Kill FX" that make combat more rewarding. In the early days of the GoldSrc engine,