Weapons play a major role as much as the shapeshifting powers of Alex Mercer and James Heller. In order to use a specific weapon, Mercer had to consume a military personnel who specialized, during base infiltrations.
There were a variety of firearms that military personnel used, though not as lethal, or destructive as offensive powers, weapons are prized for being the only ranged weapons besides the Whipfist and the Groundspike attack that Alex can use.
- Main article: Pistol
The M9 Beretta is used by police officers, and the military carries them as side arms, but cannot be used by the player. The damage it causes to Alex is the smallest in the game.
- Main article: Assault rifle
The M4A1 assault rifle is the basic weapon of the Marines and the Blackwatch soldiers. It is present from the start of the game and can be used without any training. It is capable of being fired as a fully automatic rifle, or in three-round bursts.
- Main article: Machine gun
The M249 provides fast and vast amounts of firepower, despite being slightly weaker than the assault rifle. Though it has slightly less power, it carries many more bullets, making it a better choice for longer term use.
- Main article: Grenade launcher
One of the most common weapons that Alex has access to, the M32 Multiple Grenade Launcher is a useful weapon because of its range, power, and accessibility. Skill in using a grenade launcher can also be upgraded by absorbing enemy memories to the point where it can destroy a Hive with ease.
- Main article: Missile launcher
The FGM-148 Javelin, is much more powerful than the grenade launcher, and fires guided missiles as opposed to dumb-fire projectiles, but possesses a much smaller ammo size, and is a harder to use in close quarters. It is best used against either targets with large health (buildings, tanks, hunters) or larger groups of weaker enemies, one shot taking out most of the group.
|Assault Rifle 1||Behind the Glass||Consume|
|Assault Rifle 2||A New Order||Consume|
|Assault Rifle Max||Errand Boy||Consume|
|Machine Gun 1||A New Order||Consume|
|Machine Gun 2||Biological Imperative||Consume|
|Machine Gun Max||Shock and Awe||Consume|
|Grenade Launcher 1||A New Order||Consume|
|Grenade Launcher 2||Errand Boy||Consume|
|Grenade Launcher Max||Biological Imperative||Consume|
|Missile Launcher 1||Errand Boy||Consume|
|Missile Launcher 2||Biological Imperative||Consume|
|Missile Launcher Max||Children of Blacklight||Consume|