An automatic grenade launcher that fires 25mm grenades with less of a projectile fall off than traditional grenade launcher.(sic) This feature makes the weapon more accurate, smart technology for smart players.
The Arbiter is a semi automatic grenade launcher that boasts a relatively high rate of fire and ammo capacity at the expense of damage. Among grenade launchers, it possesses the second largest magazine, the highest reserve capacity, and the lowest damage per shot.
The Arbiter stands out among the rest, however, with its drastically reduced grenade arc, allowing it to more accurately shell down enemies behind cover or even act as a makeshift sniping weapon within a certain range. In this sense, it is more akin to a smaller, weaker HRL-7 with a magazine rather than a conventional grenade launcher. Also, it is the only grenade launcher with a detachable magazine, allowing for speedy reloads when needed.
In order to unlock the Arbiter and its mods, one must complete special side jobs from Gage. To complete the jobs, the players must collect four separate weapon cases and their keys from the Rats, Firestarter, Framing Frame and Big Oil heists.
An Arbiter can be found on the table in Chain's workshop. As the player collects the Arbiter's part kits, the copy in the workshop will progressively gain more components until it is replaced by the actual launcher upon collecting all 4 cases. It will not have modifications, even if the player's Arbiter has mods.
It is highly advised to not use the Arbiter around Tasers. Their shock attack will cause you to forcibly launch the grenade, which is very likely to get you, your crew, and hostages killed. If a Taser is spotted (or heard charging his weapon), quickly neutralize him or switch to another weapon if there is not enough time to locate the Taser.
Due to the reduced arc compared to the other lauchers, the Arbiter can be considered a smaller brother to the HRL-7 with a bigger magazine. As such, it can be better used to counter-snipe Snipers (and unlocking an achievement for doing so enough times) than other grenade launchers and the player won't need to manually compensate for the drop that much.
The grenades fired from the Arbiter also has a tendency to ricochet off surfaces, thus eliminating enemies at close range (as a last resort) can be an issue. If not considered, grenades may bounce off and miss intended targets. This can especially be true with Shields.
Similar to the HRL-7, bringing an Ammo bag is all but mandatory if the player wants to make extensive use of the Arbiter. Otherwise, eliminating a large group of common enemies with a grenade can provide enough ammo drops to refill at least one spent grenade.
A fully automatic weapon should be paired with the Arbiter to counter its low rate of fire and lengthy reload time. A shotgun can be acceptable as well if players do not want to risk self-injury at close range.
The Arbiter can be wielded to bombard areas, especially if a wielder is in Swan Song.
The Bulldozer's metal face platings can be shot off with two well placed grenade blasts in quick succession and the user or another teammate can use a rifle to eliminate the special unit.
It may be more recommended to utlize incendiary grenades for the Arbiter instead of attempting to use it like the China Puff 40mm. An Arbiter loaded with incendiary grenades can provide quick area denial and damage many units caught in the fire while the operator is capable of carrying a more suitable primary weapon.
This modification does not incur a hit to Concealment even though it protrudes quite a bit from the Arbiter's original muzzle. In fact, equipping it to the weapon will improve its Concealability by a substantial margin.
Although the main flashlight has a toggle switch, the laser sight component of the LED Combo is pressure-activated, meaning the laser will stay on as long as the pressure switch is depressed. This switch is not placed where it should be, however (on foregrips, magazine wells, etc...) and is instead ziptied to the main taclight, leaving no plausible mean for the user to toggle it without awkwardly moving their off hand off the weapon and gripping the attachment itself.
Requires a pre-installed sight mod to mount. The magnification level can be changed while aiming down the sights, and the aiming FOV will automatically adjust itself. Not compatible with the Acough Optic, Military Red Dot, Milspec Scope, Combat Sight, Reconnaissance Sight, Theia Magnified Scope, Box Buddy Sight, the JP36's Original Sight, the Raven's Flip-up Sight or the GROM and Platypus 70's iron sights. Currently bugged and not appearing as intended on certain weapons, for a list see here. They're still listed below even if broken.
Upon release, the default reticle of this sight was a chevron instead of the retail version's red dot. After the release of the Gage Mod Courier DLC, it was reverted to the regular sight's red dot.
It is functionally the same as the standard Military Red Dot Sight, but the sight's casing is tan instead of black with the line "A-10" scrawled on near the adjustment knob. The sticker on the lens cap's interior also says "I <3 Payday" instead of having a picture of an American flag.
This sight was based on the Aimpoint CompM2 optic. While it is portrayed as a high-zoom scope in-game, the CompM2 is actually a reflex sight, meaning it offers no magnification in reality.
The Last Man Standing ([✓] Arbiter - Last Man Standing) skin's name was made by a friend of the skin's creator. The skin bears many instances of XXV-100, which translates into "Reputation level 100 - Infamy XXV", the highest rank a PAYDAY 2 player can possibly achieve up to this point.
The skin's texture falsely claims the Arbiter is capable of Auto fire, despite the XM25 being a semi-automatic design.
The Arbiter is based on the XM25 CDTE, albeit without the weapon's signature rangefinder-smart munition controller scope which does not allow the user to set where to detonate the grenades. A rail mount is present in place of the scope to enable the use of sight mods instead.
This shortcoming restricts the Arbiter to dumbfiring only, which defeats the XM25's purpose entirely and dumbs it down to the level of the GL40 and Piglet. It still has the control buttons on its integral foregrip, however.
Despite being specifically developed with airbursting in mind, the 25x40mm grenades fired by the Arbiter do not have the ability to actually detonate in mid-flight and will only explode if they hit something solid.
"Arbiter" means "a person with power to decide a dispute" or "a person or agency whose judgment or opinion is considered authoritative."
Previewing the Arbiter in the inventory shows it with its bolt locked back, implying it's an open bolt weapon, even though the real XM25 fires from a closed bolt.
The Arbiter is the first weapon to require players to surmount an additional puzzle before becoming available for purchase.