Knockout (Abbreviated as "K.O") is when the user "kills" the opponent by making their health bar to zero. Some games contain weapons, or gear, which most of them are for fighting players.  For example, you would probably find weapons in a swordfighting game (KOs are Knockouts, are usually the main objective). Sometimes, a user could "kill" another user after he himself has been killed. This can be the effect of hacking, or lag (especally connection lag). In 2006, KO's would not register to the roblox user's profile.