Quick summary
- The decoy is the cheapest grenade in CS2 at $50, and it is not trying to hurt anyone.
- It copies the firing sound of the most powerful weapon you are carrying. That is the whole point. You are buying a second of somebody else's attention.
- The Counter-Strike Wiki puts the self-detonation at roughly 18 seconds and publishes a CS2 damage table for the blast. CSDB's guide, reviewed in July 2026, says about 15 seconds of fake gunfire and about 5 HP of damage. Those two do not agree, and I would not plan around the damage number.
- It is a pistol round purchase. That is where $50 makes sense.
The decoy lands, waits a moment, then plays the firing sound of your best weapon. Enemies who hear it have to decide whether somebody is really there.
The wiki describes it as mimicking the most powerful weapon you are carrying. If you have no firearm equipped, it falls back to the starting pistol: the Glock-18 on the Terrorist side, the P2000 or USP-S on the Counter-Terrorist side.
On your own team's radar the decoy shows as a grey dot rather than a player marker, so you can tell your teammates what you just threw without typing it.
The model is a clone of the flashbang with a red stripe where the flashbang has its own. That detail matters more than it sounds. The wiki notes that an enemy who catches it in the air can back up and look away, the same way they would at a flash, which leaves a short window to move in while they are recovering.
It counts toward the four grenade cap, it does not share a slot with any other grenade type, and you can carry one of them.
The damage question
This is where the sources part company, and it is worth knowing before you rely on it.
The Counter-Strike Wiki gives a full CS2 explosion table for the self-detonation: 21 damage to an unarmored head, 23 to chest and arm, 19 to abdomen and pelvis, and 11 to an armored head. The wiki also records that the blast does not damage teammates and that the kill feed will not show a headshot icon if the enemy dies to the explosion.
CSDB's guide describes the decoy as roughly 15 seconds of fake gunfire followed by an explosion worth about 5 HP.
Those are not the same claim. The wiki is reporting the game's internal damage table. The guide is reporting what it feels like in a match. Either way the decoy is not a kill tool. It is a distraction that occasionally finishes somebody who was already one bullet from death.
When to buy one
Pistol rounds. That is the honest answer. $50 is small enough that you can buy it and still afford armor or a better pistol, and the information it buys is worth more than $50 in a round that is decided by who shoots first.
It also works as a cheap way to fake a push on an eco round. Beyond that I would treat it as a situational purchase rather than a default one, because the sound is identical every time and experienced players stop reacting to it.
Source