Alyx's Gun is an average sized, easily concealed pistol with a 30-round magazine housed in the grip, and is capable of both semi-automatic (seen in Half-Life 2) and automatic fire (seen in Episode One).
Though it is unknown what kind of ammunition it fires, it does roughly the same amount of damage as the USP Match. Since the actual name of the pistol is never given and it has no real life counterpart, it is possible that it is unique and was manufactured by the Resistance, Alyx herself or Black Mesa.
Alyx is the only NPC ever observed using this weapon. The player never acquires it in normal gameplay. Alyx appears to have unlimited ammunition for this weapon, possibly due to her being a NPC. When she is not using it, she apparently replaces it inside her jacket, probably in a holster.
- During the first two chapters of Episode One and a brief period in Episode Two, Freeman only has the Gravity Gun and has to rely on Alyx to dispatch enemies, depending on the availability of physics objects to use as ammunition. Alyx is a fairly good shot, but she must not be left dealing with too many enemies by herself, or she can get overwhelmed and be killed.
- Alyx's gun has the advantages of being automatic and high accuracy (even better than the MP7 or the OSIPR when used by Rebels); at longer ranges Alyx has little trouble to handle most enemies and rarely gets killed due to most enemies having poor accuracy combined with her own health regeneration.
- On the downside, it has low damage, a problem can be when engaging a high health enemy or enemies who are in groups, in fact the firepower is quite insufficient at closer ranges and enemies armed with weapons like the shotgun or the MP7 can sometimes outgun her weapons especially if they are in pair. Alyx often requires assistance from other allies; protecting her is necessary.
Behind the scenes
- In the playable Half-Life 2 Beta as in the retail Half-Life 2, the weapon can be spawned and used by the player, suggesting it was to be used by the player at some point. The viewmodel is however missing and the weapon will improperly appear on the left of the screen as the worldmodel. Furthermore ammunition does not exist, although it can be overridden with the console code "sk_max_alyxgun #", which sets the maximum ammo. Default maximum amount is 150.
- In the Half-Life 2 files, several texture files for HUD weapon icons can be found, most of which still containing the icons for almost all of the cut weapons. Alyx's Gun is among them, giving more clues about a possible original use by the player.
- Closer look at the model's animations in the Source SDK show it can be converted to both a rifle and a submachine gun, having a retractable stock, front folding grip and extended barrel with silencer, never seen in-game.
- During the elevator ride with Mossman in Black Mesa East, one of the Rebels working on the generators with the Vortigaunts is holding Alyx's Gun in his right hand. This is probably a developer's oversight, or the remnant of an early test of other NPCs using the gun.
- Alyx's Gun appears to be custom-made from parts that come from USP .45 and the PM-63 (with a possibility that an M1911 was used for the pistol grip), though its overall appearance bears a strong resemblance to the non-production KRISS KARD.
- The ammo's HUD icon is reused from the beta MP7's ammo icon.
- In Episode One and Episode Two, Alyx's gun must be manually picked up by pressing "USE" key; walking over it will not work.
- When the player spawns a Civil Protection with Alyx's Gun, the gun won't inflict damage, also there is no sound when they fire it. However if player spawns a Resistance member with one, they do inflict damage, but only female rebels can fire the gun in automatic mode. When used by male rebels, they fire the gun in semi-automatic mode and will run away when they approach Headcrabs and Zombies, as if they were unarmed due to Citizens has "fear" relationships to zombies and male citizens do not have strafing animations for pistols.
- Alyx's Gun in Half-Life 2 doesn't have its own firing sound, instead it uses a much louder firing sound of the USP Match. Each time Alyx fires her gun, the captions will read [Pistol Sound]. In Episode One and Two, Alyx's Gun has its own unique firing sound, which appears be more suppressed and silent. The subtitle will no longer appear when she fires it. If the player uses the Alyx's Gun in Episode One and changes the firing mode to semi-automatic and fires it, one can hear a three round burst sound effect of the MP7 but it only shoots one bullet at a time.
- When Alyx is aiming or shooting, her gun's magazine will go through her hand, likely because Alyx's Gun uses the same animations as the USP Match.