|Killzone, Killzone 2, Killzone 3, Killzone: Mercenary|
|Location||, Salamun Bridge: Bridge East, Suljeva Village|
|Rate of fire||Low|
- "A reliable side arm featuring a large clip size and good damage over range."
- —Killzone.com Description
It fires the 9.2x20mm cartridges, as written on the magazine, but holds only 12 rounds in a helical magazine on the front of the weapon. Killzone 1 featured the predecessor IvP-18 Tropov Machine Pistol, with a burst-fire feature, similar to the real world Beretta 93R; however, this feature was removed from the new weapon, most likely in favour of mass production. The weapon is still an effective sidearm in the campaign, however, as it packs as much punch as an M4 Revolver, and comes with more ammo as well. You can only find it on the ISA Cruiser level and the Suljeva Village level in the campaign.
In the Killzone 2 Multiplayer and Killzone 3 Multiplayer mode, the StA-18 is the first secondary weapon & pistol for every class. Overall, it is a substantially less powerful weapon than the M4 Revolver, requiring many shots into an enemy in order to kill him. However, it has a higher rate of fire (as well as larger magazine size) than the M4 Revolver.
Though the StA-18 requires more shots to the body to kill an enemy than the M4 Revolver, headshots are quite deadly, usually requiring only 1 or 2 shots to kill an enemy. The closer an enemy is, the more effective headshots are while using the STA18. For skilled players, it is still a very reliable and dependable weapon.
In Killzone: Mercenary, there are two variants for the handgun: the standard one, which costs V4000, and the silenced one (StA-18SE), available from the beginning of the game. The difference between them, besides the sound suppression, is that the silenced one isn't as accurate as the standard one.
- The StA-18's 9.2 mm caliber could possibly be a reference to the movie Red Heat where the main protagonist (a Soviet cop played by Arnold Schwarzenegger) uses a fictional Soviet pistol, the Podbyrin (actually a modified Desert Eagle) chambered with the fictional 9.2 mm cartridge.
- The 9.2 mm cartridge could also be a reference to the Soviet 9x18mm Makarov, which uses a 9.2mm bullet because the Soviets measured caliber by the lands and not the grooves as is done in the Western militaries. The 9x18mm Makarov is low powered enough that simple blowback operated firearms can be made without requiring as heavy of a bolt or spring to contain the pressure during cycling, but is powerful enough that armor piercing ammunition could be developed to have better penetration against body armor.
- The StA-18 demonstrates inconsistent damage outputs throughout Killzone 2.
- Its rounds were shown to be more than capable of penetrating the reinforced Helghast armour and helmet as demonstrated live by Mael Radec when he uses it to commit suicide, the bullet pierces THROUGH his head and helmet (two times), yet during gameplay it requires no less than two headshots even on Easy difficulty to kill an enemy, aside from faceshots which kills them instantly.
- StA-18s wielded by enemies also takes around 7-8 consistent shots to kill a player on Trooper, so it is presumed that the pistol's huge power is a special dramatic effect exclusive to cutscenes.
- It is so far the only weapon in Killzone: Mercenary to feature both silenced and non-silenced variants.
- This pistol appears to borrow some elements of the HK USP pistol.
- The Sta-18 also appeared in early trailers for Killzone: Shadow Fall, but were later replaced by the StA19 Reigner.
- The pistol is possibly based on the Hungarian Danuvia VD-01 pistol which had a helical magazine under the gun as well.