Quake II features eleven firearms total and six ammunitions.
| Weapon | Damage (singleplayer) | Ammo Type | Maximum Ammo | Fire Mode | Rate of Fire | Muzzle Velocity |
| Blaster | 10 | None | ∞ | Semi-auto | 133 rpm | |
| Shotgun | 48 | Shells | 100/150/200 | Pump-action | 50 rpm | ∞ |
| Super Shotgun | 120 | Shells | 100/150/200 | Pump-action | 50 rpm | ∞ |
| Machine Gun | 8 | Bullets | 200/250/300 | Automatic | 600 rpm | ∞ |
| Chain Gun | 8 | Bullets | 200/250/300 | Automatic | ~1680 rpm | ∞ |
| Hand Grenade | 120 | Grenades | 50/100 | Single | - | - |
| Grenade Launcher | 120 | Grenades | 50/100 | Semi-auto | 50 rpm | |
| Rocket Launcher | 100 | Rockets | 50/100 | Semi-auto | 66 rpm | |
| Hyperblaster | 20 | Cells | 200/250/300 | Automatic | 600 rpm | |
| Railgun | 150 | Slugs | 50/75/100 | Semi-auto | 37.5 rpm | ∞ |
| BFG10k | 200+(up to 1,000) | Cells | 200/250/300 | Pump-action | 24 rpm | ~15.2 m/s |