Over the course of his journey Gordon finds or is given a wide set of guns and grenades, that he uses to “neutralize” the combine security forces in the interests of the G-man.
| Weapon | Damage | Magazine Size | Location found/given |
| Crowbar | 10 | None | Level 2 |
| Pistol | 5 per round | 18 rounds | Level 3 |
| SMG | 4 per round | 45 rounds | Level 3 |
| Revolver | 225 headshot, 75 body shot | 6 rounds | Level 4 |
| Gravity Gun | Zero-Instant kill/Instant kill | None | Level 5 |
| Super Gravity Gun | Zero-Instant kill/Instant kill | None | Level 13 |
| Shotgun | 48 per shell | 6 shells | Level 6 |
| Pulse Rifle | 8 per round | 30 rounds | Level 7 |
| RPG | 200 | 1 | Level 7 |
| Grenade | 125 | 1 | Level 3 |
| Crossbow | 100 | 1 | Level 7 |
| Bugbait | 0(Instead of damaging the opponent it attracts Antlions) | 1 | Level 8 |