Watch Dogs 2 (sometimes stylized as "WATCH_DOGS 2") is the 2016 sequel to Ubisoft's Watch Dogs. Like it's predecessor, it is a third person shooter that gives players the liberty to include stealth and hacking, via a backdoor implemented in CT_OS, the fictionalized America's universal operating system that controls everything from walkie-talkies to street signs. Unlike the first, Ubisoft wanted to emphasize the hacking component to give players a more varied and unique combat experience that avoided the issue of the first one, in that it often played out as a totally traditional TPS in which hacking was just a neat gimmick and story mechanic, and as such, in addition to vastly increasing the capabilities and ease of the hacking mechanic, they didn't include as many traditional firearms as the first game. Of the traditional firearms existing in WD2, almost all are repeats from the first.
You follow a group of hacktivists in the San Francisco cell of a large hacker organization known as DedSec, loosely inspired by the real world Anonymous. As underground vigilantes, you are naturally criminals, and as such, instead of purchasing weapons in gun stores, you must either create them in a 3D-printer, or steal them from members of enemy factions, such as the SFPD, the Bratva, or the "Umeni Security Corps", a shady security contractor that primarily hires war criminals. For gameplay reasons, rather than creating 3D-printer weapons being a question of purchasing parts online, taking 12 hours to 3D-print a Glock lower, sanding it down, and then assembling it, you simply shove an exorbitant amount of money into a large 3d printer and fully assembled guns (almost always entirely made of metal, sometimes even wood) are spat out seconds later.
In essence this game uses 3D printers as if they are Star Trek replicators, much as "nanotechnology" was used in older near-future sci-fi (and before that "robots" and then the more traditional "magic"). Some of them, also feature "smart bullets" that "autohack" their targets, which would be impossible with 2016 technology (or at least impossibly expensive). The 3D-printed guns in-game are more or less just normal firearms with minor upgrades, though some have totally unique functionalities.
The amount of custom 3D-printed firearms is intended to make up for the reduced amount of traditional ones.
The following weapons appear in the video game Watch Dogs 2:
The Kimber Warrior appears in-game as the "1911". It incorrectly holds 10 rounds in its magazine; its real-world counterpart only holds 8 rounds in the magazine. The Kimber Warrior is never used in game by any NPCs, and thus the only way to acquire it is via 3D-printing it for the low price of $22,900.
SIG-Sauer P250 Compact
The SIG-Sauer P250 Compact appears in-game as the "P-9mm". Just like in the first game, it is incorrectly described as being Austrian, and holds 17 rounds in its magazine. It is erroneously the standard-issue duty pistol of the San Francisco Police Department and the Oakland Police Department, the former issues the SIG-Sauer P226 and P229 in .40 S&W while the latter uses the Glock 17.
The PP-2000 appears in-game as the "R-2000". Its stock has been completely removed, rather than folded to the side.
Shotguns
AA-12
The AA-12 appears in-game as the "ATSG-12". It is used by both the SFPD and the Oakland PD.
Mossberg 500 Cruiser
The Mossberg 500 Cruiser appears in-game as the "SG-90". It erroneously holds 8 rounds in its 5-round tube.
Saiga 12K
The Saiga 12K appears in-game as the "SGR-12". It has a custom buttstock, pistol grip, and railed handguard. It is used by SFPD SWAT, which isn't actually outside the realm of possibility as some American law enforcement agencies do have Saiga and VEPR shotguns in their inventories.
Franchi SPAS-12
A SPAS-12 is seen in a videogame (Rainbow Six: Siege) played by Pinkle Chris, a online troll in one of the side mission.
Assault Rifles
AK-103
The custom AK-103 from Far Cry 3 & Far Cry 4, as well as the previous game, returns as the "AK-47". Is dual-wielded by Devon von Devon (Jimmy Siska) in the trailer of the fictional movie "Cyberdrive".
IWI Galil ACE 32
The IWI Galil ACE 32 appears in-game as the "AC-AR". It is equipped with a scope and is classified as a sniper rifle. Much like the Kimber Warrior, the AC-AR can only be acquired by 3D-printing.
"OCP-11"
The fictional "OCP-11" returns from the original Watch Dogs, once again as the cheapest assault rifle in-game.
Patriot Ordnance Factory P416
The Patriot Ordnance Factory P416 appears in-game as the "Goblin". It uses the same model from the previous game, which itself originates from Far Cry 3, despite its name referring to its depiction in Ghost Recon: Future Soldier. It is used as standard-issue rifle of the SFPD SWAT, a somewhat odd choice outside of the world of Ubisoft-isms.
Machine Guns
Ultimax 100 Mark 3
The Ultimax 100 Mark 3 appears in-game as the "U100". The Ultimax is also used by SWAT, a rather questionable choice.
Sniper Rifles
SVD Dragunov
The SVD Dragunov from the first game, with its Far Cry 3 ultra-shortened barrel, later production skeletonized synthetic stock, compressed receiver (hybrid with Ghost Recon: Future Soldier's PSL-54C), and Belarusian Zenit 8x42 POSP scope reticle, reappears in Watch_Dogs 2 as the "SVD". It is incorrectly used by SFPD and Oakland PD snipers.
Fictional 3D-printed guns
Handguns
"4N00bs Pistol"
The "4N00bs Pistol" is based off of the Kimber Warrior, and is in fact just a slightly modified model of the game's "1911".
"Core Dump Pistol"
The "Core Dump Pistol" is nearly identical to the "4N00bs Pistol", but with an added suppressor and scope.
"Help Desk Denial Pistol"
The "Help Desk Denial Pistol" once again is a modified version of the game's "1911" model, albeit with a larger slide and extended magazine.
Assault Rifles
"DOT_EXE Rifle"
The "DOT_EXE Rifle" is heavily based off of the UMP45.
"HHOS Rifle"
"DOT_FILE Rifle"
"Zero Day Rifle"
Shotguns
All of the 3D Printed shotguns in Watch Dogs 2 are based primarily off of the Benelli M4 Super 90.
"Bullet Hell Shotgun"
The "Bullet Hell Shotgun" is based off the the Benelli M4 Super 90, with a skeletonized stock and pistol grip, and with a handguard resembling that of a typical pump-action shotgun's pump.
"DDoS Shotgun"
The "DDoS Shotgun is also based off the Benelli M4 Super 90, with what appears to be a skeletonized collapsible stock and pistol grip, railed handguard, and is fitted with a box magazine.
"Goodbye, World Shotgun"
The "Goodbye, World Shotgun" is once again based off of the Benelli M4 Super 90, this time with a pistol-grip only stock, and using a drum magazine. The handguard appears to be based off of the heatshield on the Franchi SPAS-12
Sniper Rifles
As an interesting note, all 3D-Printed sniper rifles in Watch Dogs 2 are covered in spikes, most notably on the cheekrest. This would obviously prevent the cheekrest from being used safely--the recoil from firing would potentially cause severe trauma. However, the spikes do not have any impact on gameplay, and were likely added to make the 3D-printed snipers more visually distinct.