While there isn't a complex weapon customization system, many weapons in Far Cry 3: Blood Dragon come with pre-installed attachments or unlock upgrades as you progress. These enhancements improve weapon performance, making them more effective in combat. Attachments are often unlocked by completing specific side quests, such as Hunting Quests, or by progressing through the main story.

- Red Dot Sight / Scope: Improves aiming accuracy and provides a clearer sight picture. Essential for precision shots.
- Extended Magazine: Increases the ammo capacity of a weapon, allowing for longer sustained fire before reloading.
- Suppressor: Makes a weapon silent, crucial for stealth operations. The A.J.M. 9 comes with one, and some other weapons might gain one.
- Explosive Arrows (Bow): Transforms the Bow into a powerful explosive launcher, adding area-of-effect damage.
- Incendiary Rounds: Some weapons might gain the ability to fire incendiary rounds, setting enemies on fire.
These upgrades are automatically applied once unlocked. Always check your weapon stats after completing quests to see if any new attachments have been added. They significantly impact how you approach combat, making your favorite weapons even more deadly.