Gamer is a 2009 sci-fi/action film starring Gerard Butler as a former soldier turned convict who is forced to participate in a massive online shooter game where advanced mind-control technology enables real humans to be controlled by online players.
The following weapons were used in the movie Gamer:
During the opening battle, Kable (Gerard Butler) gets surprised in the middle of reloading his G36C, but manages to pull out a FN Five-seveN, and execute the other Slayer.
Glock 17
During the 27th battle, a Slayer in the background is using a Glock 17.
Kel-Tec PLR-16
Before Kable's last battle, a Slayer is seen loading up a Kel-Tec PLR-16 Pistol with a 30-rounder STANAG magazine.
Submachine Guns
FN P90
The FN P90 submachine gun is the standard firearm for the prison guards guarding the "Slayers". Later in the movie a group of "Slayers" are seen armed with P90's with laser sights, when Castle sends them to kill Kable and his wife in Society City.
Heckler & Koch UMP45
Another "Slayer" in the first mission appears to be using a Heckler & Koch UMP45.
Rifles
Heckler & Koch G36C
Kable's standard weapon in Slayers is the G36C rifle with a tri-rail handguard fitted with a vertical foregrip. Like all the Slayers' weapons, the rifle has an electronic safety mechanism that renders the weapon useless when the game is not in progress. On some movie posters, the G36C with CM203 is outlined and identified as an "M4" even with a little line drawing of an M4 in a box (seen above).
Heckler & Koch G36KV
Kable (Gerard Butler) uses a H&K G36KV rifle fitted with a Beta C-Mag and a foregrip during his 28th game of Slayers.
FN F2000 Tactical
F2000 Tactical rifles are used by most of the "Slayers". This appears to be the "starter" weapon for all beginning- and lower-level Slayers. As they survive more battles, the Slayer's "Gamer" can purchase newer weapons and modifications. All of the weapons used by the "Slayers" have a safety mechanism attached on the front sights that renders the weapon useless when the game is not in progress.
Later in the movie, "Slayers" sent by Castle to kill Kable and his wife in Society City are armed with FN F2000 Tacticals; in place of the electronic safeties, these rifles have laser sights attached.
CIS SAR 21
A "Slayer" during the opening battle appears to be using a CIS SAR 21 rifle.
Shotguns
Saiga 12
Hackman (Terry Crews) uses a modified Saiga-12 shotgun in a pistol-grip-only (PGO) form as his main weapon, before it is later taken by Kable when he decides to escape Slayers. The weapon has a 10-inch barrel with a muzzle attachment, serving as an adapter that allows the stock length gas system to cycle blanks. Above the gas tube is a standard rail similar to the UltiMAK, and of course, the safety device which allows or prevents the weapon from firing after a battle is over. The drum, a 20 round "Wraithmaker" is apparently filled with solid slugs. The forward grip appears stock.
During the 29th game of Slayers, Hackman aims the weapon at Kable and pulls the trigger, only for the electronic safety to re-engage. In defiance of all logic, the gun expends the unfired shell down the barrel to plop on Kable's head, as if emphasizing how close he came to dying (i.e., as if the safety interrupted the firing before the hammer hit the round, but still allowed the round to be ejected).
Mossberg 500 Bullpup
During Kable's 29th battle, a "Slayer" can be briefly seen with a Mossberg 500 Bullpup.
Machine Guns
Browning AN/M2 (flexible mount)
Browning AN/M2 flexible machine guns with and without cosmetic barrel shrouds are carried by a few of the Slayers, and are also used as automated turrets during the games.
M249 SAW Paratrooper
One of the "Slayers" of the game (credited as "Mean Slayer") is shown firing a M249 Paratrooper machine gun with a large barrel shroud and a side-mounted foregrip.
Other
Cobray 37mm Launcher
Later in the movie, Kable is upgraded to a Heckler & Koch G36C fitted with a short-barreled Cobray 37mm Launcher, which fires a "smart" grenade with multiple guided antipersonnel warheads.
Flamethrower
Flamethrowers are used by some of the Slayers, most noticeably during Kable's 28th battle.