Counter Strike Online Wiki

For the original version, see USAS-12.

Room restrict shotgunSKULL-11 is a SKULL shotgun in Counter-Strike Online.


Empty slot This weapon has Part System installed.

SKULL-11 is the modified version of Korean USAS-12 fed with 28 rounds of 12 Gauge Anti-Zombie. It carries a special gauge that can deal critical damage to zombies and equipped with a slug mode as secondary fire. Slug mode concentrates the gauges to be in narrow space, making SKULL-11 ideal for long range engagements too.


  • High magazine capacity for a shotgun
  • High damage and stun power, especially to zombies
  • High rate of fire
  • Very effective at middle/far range if using the slug mode
  • Very accurate when using slug mode
  • Can penetrate Kevlar
  • Low recoil


  • Obtainable only through limited time events for cash points
  • Expensive price and ammunition cost
  • Low rate of fire in slug mode
  • Slower movement speed when reloading
  • Cannot penetrate walls, objects or bodies in both modes
  • Cannot be fired while reloading
  • Unusable scope
  • Low spare ammo

Release date[]

  • South Korea: 19 April 2012.
  • Taiwan/Hong Kong: 24 April 2012.
  • China & Japan: 25 April 2012.
  • Singapore/Malaysia: 9 January 2013.
  • Indonesia: 2 January 2013.
  • CSN:Z: 23 September 2014.
  • Turkey: 8 October 2014.
  • Vietnam: 26 March 2015.


Mode Buy cost Ammo cost (1 mag) Ammo cost (Total) Total
Original $6500 $175 (20 rounds) $350 (40 rounds) $6850
Scenario $6500 $175 (20 rounds) $5250 (600 rounds) $11750

  • SKULL-11 is very effective at clearing crowds of zombies with buckshot mode.
  • Recommended when facing Juggernaut due to his big body.
  • Not recommended when facing Ganymede because SKULL-11 is very heavy, it need proper skills to dodge his rush attack and the pellets won't do much damage if using buckshot.
  • Not recommended when dealing with bosses in middle/far distances, because the pellets won't do much damage.
  • Slug mode is not very recommended due to its low rate of fire and no penetration for both modes.
  • SKULL-11 can break barriers easily.
  • 28 rounds of SKULL-11 can deal around 12,000 damage to Bosses (Provided the firepower has been maxed).
  • Can take down the Titans easily.
  • Slug mode is very effective when facing Troopers and Lancers in long range.

  • For close range, use primary fire mode while for middle/long range, use secondary fire mode.
  • Switch to secondary weapon when escaping and find a safe place to reload.
  • 28 rounds of SKULL-11 can deal about 3136 ~ 6272 damage to zombies.
  • Use it in ducts/closed areas for maximum performance.
  • Aim for newly infected/common zombies as they're weak and can be killed easily in close range.
  • In close range, aim for the head or chest for maximum damage.

  • Not recommended in Original because it is very expensive.
  • Recommended in Deathmatch, Team Deathmatch, Basic and Item Battle because it can mess up your opponent aim and has high stun power when firing continuously at enemies so that your enemies can't escape.
  • Ideal when dealing with large amount of enemies.
  • Note that SKULL-11 can penetrate Kevlar, use it as an advantage.
  • It is very powerful in close range and has high rate of fire/ammo. Closed maps such as Italy, 747 and Estate are the ideal places to use SKULL-11.
  • Switch to Slug mode when dealing with enemies at far distances.

  • Tactics facing SKULL-11 users[]

    Classic Battle[]

    • They're slow and have long reload speed, but deadly with their 28 rounds of 12 Gauge Anti-Zombie in close or middle range. Be aware of their appearance in closed maps such as Italy and 747.
    • In middle range, 5-7 shots from SKULL-11 users will mess up your aim and stun you, or even kill you. So try to annihilate them quickly.
    • In long range, they have to use Slug, so the rate of fire is slow, use this as an advantage.
    • Surprise attack is recommended.

    Zombie Infection[]

    • SKULL-11 can't dig through walls or obstacles, so mostly you'll survive and can protect your zombie teammate if you have a massive amount of 8000HP and up if you're in Ducts. 
    • SKULL-11 has a high stun power, making the victim hard to move after being shot.
    • Run immediately when the user turn on Deadly Shot if you have less than 5500 HP.


    USAS-12 Camouflage
    • Lighter (-3%)
    • Higher clip size (+8)
    • Can be obtained from Shop
    • Effective in long range
    • Higher damage to zombie (+51)
    • Able to switch to slug mode 
    • More expensive (+$3150)
    • Lower damage to human (-5)
    • Higher recoil (+2%)
    • Lower fire rate (-2%)
    • Expensive ammo cost
    • Low rate of fire when using slug mode

    • Higher damage to humans (+2) and zombies (+58)
    • Higher clip size (+21)
    • Higher reserve ammunition (+8)
    • Cheaper ammunition cost
    • Limited edition
    • High stun power
    • Lower rate of fire (-1%)
    • Higher recoil (+2%)
    • Heavier (+16%)
    • More expensive (+$750)
    • Cannot be fired while reloading
    • Cannot do explosive shot



    • United Kingdom: Seen carried by a SAS operative in some promotion posters.


    Shooting sound

    Drawing sound

    Reloading sound


    • The SKULL-11 features iron sights, which were not present on the original USAS.
      • The scope has the words Aopoint on the side, a word play/corruption of the real-world company Aimpoint. It also reuses the same scope from SKULL-3 with a different mount, which means that it's capped off and therefore unsusable.
      • This weapon is the second shotgun with an unusable optic sights after SPAS-12 Superior.
    • The word "DEATH ROAD" and the serial numbers "54054-01" can be seen on the weapon's handguard, and the writing "SKULL-11" is located behind the ejection port.
    • When reloading, the user's speed will decrease momentarily. The M134 exhibits this behavior as well.
    • The SKULL-11 is the only shotgun that's able to fire slug rounds and switch between pellet types on the go.
      • The "slug rounds" in-game are essentially pellets tightly grouped together into a single point.
    • SKULL-11 and SKULL-9 are the only weapons in the SKULL series that cannot go through objects.