The Overwatch Standard Issue Pulse Rifle (OSIPR), also known as Pulse Rifle or AR2 (Assault Rifle 2; stemming from a development codename), is a Dark Energy /pulse-powered assault rifle manufactured by the Combine.
It has a 30-round magazine, which is reloaded with an automatic mechanism built into the weapon. A Dark Energy Ball shooter is built into it; the orb is capable of disintegrating almost anything it touches. On the body can be seen the alphanumerics "V952", also featured on other Combine devices.
While the OSIPR is common amongst the Overwatch forces, only Overwatch Elite are allowed to fire the Energy Balls. If the Overwatch Elite is killed, they will drop an Energy ball and the player can pick it up.
Rebels often capture OSIPRs for their needs. Notably, a Rebel at White Forest informs his comrades that the weapon's secondary attack can be useful against Hunters, leading to the AR3 dispute. While similar, the mounted variant, the Emplacement Gun, is a different pulse gun.
The player first acquires the weapon at the end of Half-Life 2's sixth chapter, "We Don't Go To Ravenholm...", scavenged off of a dead soldier previously fighting stray Zombies coming out of Ravenholm. In Episode One, it can be found in a Combine supply room in the chapter Urban Flight. In Episode Two, it is found in a doorway in the chapter Freeman Pontifex, near a small overrun Resistance outpost.
The player first acquires the Energy Ball at the end of chapter "We Don't Go To Ravenholm...", in the warehouse where Rebels fight Overwatch soldiers. In Episode One can be obtained by killing an Overwatch Elite in the Hospital. In Episode Two can be obtained in a Supply Crate appearing on the Car Radar before the White Forest Inn.
- The OSIPR's recoil is extremely strong. The weapon's spread is much worse when firing the weapon in automatic mode, so firing it in short bursts is highly recommended (this also conserves ammo). Furthermore, the player can only hold three full magazines (that is, one in the gun, two spare), which are easy to go through if firing in automatic mode.
- Since the amount of ammo the player can carry for the OSIPR is relatively low and it burns through ammo very quickly if not carefully managed, it is best used in situations where nearby ammo is plentiful - that is, when fighting Combine Soldiers as a rifle dropped gives much more ammo compared to the MP7.
- In most situations, the OSIPR is better than the MP7, and is a good all-around automatic weapon. While the MP7 has a higher rate of fire and bullet capacity, the OSIPR compensates with the much higher damage per shot.
- Take advantage of its high stationary accuracy and go for headshots if possible. This helps to kill the enemy faster than usual and save ammo for later.
- The cores powering the weapon's alternate fire are rather hard to come by and should be preserved for special cases. They are efficient on lined up enemies, since it goes through them all before it hits a wall. Using it in small rooms is also efficient, since it bounces on the walls, floor and ceiling. However, use in outdoor environments where the sky is exposed is unwise, as the projectile orb disintegrates upon flying out into open air, therefore shortening the use and value of the weapon. Also, the orbs are programmed to be a fast projectile rather than hitscan bullets. Take your time to adjust aim, as it takes about 1 second to launch an orb when the trigger is pulled.
- The cores are also a one-hit-kill against even a Hunter (note that the Energy Ball is destroyed when it hits the Hunter).
- OSIPR-fired Energy Balls can be deflected by a blast made with the Gravity Gun, by capturing it. This happens whether or not the Gravity Gun is infused with the Citadel's Dark Energy.
- Energy Balls can be used to kill Striders, but they only do around a third of the damage of the RPG rockets. And seven RPGs are required to take it down so therefore, it's unwise to use it at all.
Behind the scenes
- At one point in Half-Life 2's development, there were three assault rifles: added to the OSIPR, there was the AK-47 (or AR1) and the Incendiary Rifle that used a slightly different OSIPR model and functioned as a Flare Gun with a five-round magazine. The OSIPR was originally slated to be an OICW and would be the Combine's weapon of choice. All three weapons were finally scrapped. Instead, the Incendiary Rifle's model was turned into the OSIPR's, which became the only assault rifle in the final game. The OSIPR's model still uses the name of the original model ("v_irifle").
- Gordon holds the OSIPR with only one hand. This is merely a design oversight.
- Originally, the Energy Ball could disintegrate Barnacles only in Episode Two. In the other episodes, it would merely pass through the creature without harming it. It has now been updated so that it disintegrates Barnacles in every game.
- The reload animation used by NPCs for this weapon was recycled from that of the OICW. Therefore, though in the viewmodel it is reloaded internally using an automatic system, when used by NPCs it appears to reload manually and externally. The reload for the NPCs is a manual reload, where the NPC pulls a magazine out and pushes it into the gun, like an MP7. Bizarrely, though, there is a finished reloading animation specifically the OSIPR made for Rebels of them pulling out an ammo cartridge and inserting it into the proper location. After inserting a new magazine, the NPCs also pulls the charging handle even through OSIPR doesn't have one.
- When fired by NPCs, the OSIPR uses sounds recycled from that of the OICW. Similarly, the APC's pulse gun sounds just like the player's OSIPR.
- While the reload animation is featured in the NPCs, it is not in the viewmodel.
- The recoil of the OSIPR will reset abruptly if firing a large amount of rounds on full-auto. This is most easily seen by modifying the magazine size to 40 or higher.
- Rebels holding an MP7 will always replace their weapon with the OSIPR. In Half-Life 2, Rebels armed with a SPAS-12 generally retain their weapon, while in Episode One and Episode Two they will swap the shotgun with the OSIPR.
- When Rebels pick up an OSIPR they say words like "Nice", "Awesome" and "Fantastic!".
- NPCs can only fire 25 rounds before they need to reload. However, Grigori is the only NPC able to fire 30 rounds, and while doing this in full-auto mode the recoil will not increase.
- Its ammo symbol in the HUD resembles the shape of the early energy core model.
- NPCs armed with the OSIPR are unable to fire the weapon when enemy is at point blank. Therefore NPCs armed with this weapon will always move backward when they have physical contact with an enemy, unless that NPC has melee attacks.
- Though only Overwatch Elites can fire the energy ball, the OSIPR that Gordon gets from an Overwatch soldier can fire them. This may be because they simply do not have the ammunition and are not allowed to use them, but this makes no sense as energy cores can be found in plain sight a few feet away on occasion.
- It is possible to get the OSIPR in Direct Intervention after getting the transmission by going in and out of the elevator so the combine can spawn, and allowing Alyx to kill them and the weapon won't disintegrate and you can pick it up.
List of appearances
- Half-Life 2 (First appearance)
- Half-Life 2: Deathmatch (Non-canonical appearance)
- Half-Life 2: Lost Coast (Non-canonical appearance)
- Half-Life 2: Episode One
- Source Particle Benchmark (Game files only) (Non-canonical appearance)
- Half-Life 2: Episode Two
- Half-Life: Alyx