The Zeus x27, more commonly referred to as the taser or stun gun, is a piece of equipment featured in Counter-Strike: Global Offensive. It can only be shot once before being automatically dropped, but is capable of killing an enemy in one hit. It can only be bought in Casual Mode while it is greyed out in the buy menu for Competitive Mode.
Never rush with this weapon (unless you suspect that there is only one enemy player and/or you have present team members). If there are two or more opponents, they can easily eliminate you before you can fire the Zeus x27 or switch to a more suitable firearm.
Instead, this taser mainly serves as a last resort when you are cornered by assaliants. If both your primary and secondary weapons have to be reloaded, you can retreat and hide around a corner with the taser.
Do not wield this weapon when you are in wide-open areas! Players with sniper rifles may target you first as being armed with the Zeus x27 can make it nearly impossible for users to fight back aganist opponents who are far away and/or are close to other allied players.
Due to this, use the taser in enclosed areas or nearby entryways. Generally, once after an intended target appears within your sight and is in close proximity, that opponent will normally not have sufficient time to counter your strategy.
Stay away from users and whenever possible, throw an HE grenade at their location especially when they are suspected to be hiding around a corner or an impenetrable surface.
If a lone opponent fires the Zeus x27 and misses you, it is possible to rush at that player with nearly any weapon you have, including the knife. Note that it is vital to prevent users from recovering their mistakes.
In some instances, players can hide behind a hostage and can make it easier (or harder) for users to fire the Zeus x27! To counter this, force them to switch to a less suitable firearm by moving away from them or assault the enemy with additional team members.
Other than the HE grenade, the Zeus x27 is the only non-explosive lethal equipment which functions as a weapon.
The Zeus x27 seems to have high ampage electricity because of its one-hit-kill; most tasers only shock or stun.
The Zeus x27 is the only equipment which does not exist in real life.
It is odd that the Terrorists can also purchase this weapon as the Zeus x27 seems more fitting as a Counter-Terrorist exclusive equipment. It could be likely that the Terrorists were able to somehow circumvent the availability of the weapon through the black market or modified a civilian Tazer, although this may have been implemented for gameplay balancing reasons, similar to the Molotov Cocktail and the Incendiary Grenade.