Counter Strike Online Wiki

For the original version, see M14 EBR.

The SKULL-4 is a dual wielded assault rifle in Counter-Strike Online categorized under SKULL Series.


This is a special anti-zombie rifle that is dual-wielded. It holds 48 rounds (24 rounds each) that are developed by the government. They're made specifically to deliver critical damage to zombies.


  • Very high damage to zombies
  • High accuracy in the first 4 shots
  • High clip and reserve ammunition
  • Penetrates up to 4 objects in a row
  • Light weight
  • Usable scope


  • Expensive price and ammunition cost
  • Low rate of fire
  • High recoil
  • Obtainable with cash points and during events only
  • Low accuracy in continuous firing

Release date[]

  • South Korea: 4 April 2013 (Reservation Ticket); 11 April 2013 (full release).
  • Taiwan/Hong Kong: 16 April 2013 (Reservation Ticket); 26 April 2013 (full release).
  • China: 25 April 2013.
  • Singapore/Malaysia: on 7 May 2014.
  • Indonesia: 18 June 2014.
  • CSN:Z: 23 September 2014.
  • Vietnam: 26 March 2015.


  • Its high damage can kill an enemy in 2-3 shots. However, note its low rate of fire.
Zombie modes
  • 48 rounds of SKULL-4 can do around 2400 damage to zombies.
Zombie Scenario
  • 48 rounds of SKULL-4 can deal up to 6000 damage to zombies and 24,000 damage to bosses, noted that attack power has been maxed and this excludes any item that affects the damage inflicted to them.
  • It is recommended to use the Drop + Buy tactic. Drop the empty weapon and rebuy the same one to continuously damage the bosses.
  • This weapon was the most efficient weapon to damage Kraken in Panic Room.



  • Higher damage (+32)
  • Lighter (-21% speed reduction)
  • Usable scope
  • Faster reload time (-0.1 seconds)
  • Same reserve ammunition (240)
  • More expensive (+$2150)
  • Less accurate (-11%)
  • Higher recoil (+6%)
  • Lower rate of fire (-13%)
  • Lower clip size (-22)


  • Available crosshair
  • Lower recoil (-3%)
  • Higher rate of fire (+2%)
  • Lighter (-8%)
  • Higher clip size (+24)
  • Less accurate (-2%)
  • Longer reload time (+1.4 seconds)
  • Lower damage (-17)
  • More expensive (+$150)
  • Accuracy changes when firing without scope



Firing sound



  • SKULL-4 is the first weapon in the SKULL Series to have an even number in its name.
  • The time gap between the release of SKULL-4 and the release of the last odd-numbered SKULL Series weapon (SKULL-11) in South Korea is almost exactly a year.
  • Its firing sound is similar to SKULL-1 because of the "ka-ching" sound reference.
  • This is the first dual-wielded semi-automatic assault rifle with usable EOTech sights in Counter-Strike Online.
  • This is also the first dual-wielded weapon that is able to zoom in Counter-Strike Online, the second one is Dual Kriss Custom. Realistically though, it's impossible to aim down sights with dual-wielded weapons.
  • The EOTech sights for this weapon are not attached properly and they don't have transparent lens for each of them.
  • Unlike other dual-wielded weapon's HUDs, SKULL-4 displays the HUD icon as a single gun overlaying another due to its length.
  • Oddly, the SKULL-4 is lighter than the dual-wielded SKULL-3.
  • In the Indonesia region, SKULL-4 was released before SKULL-5.