Throughout the campaign and certain Spec Ops missions, you'll encounter various collectibles and pieces of intel. These items often provide deeper insights into the game's lore, character backstories, or the overarching narrative. While not always essential for completing the mission, collecting them can unlock achievements, provide bonus XP, or reveal hidden details. Keep an eye out for glowing objects or interactive prompts in the environment.

- Intel Documents: Found on desks, tables, or in specific locations, these provide narrative context.
- Weapon Blueprints: Sometimes hidden in campaign missions or unlocked via challenges, these offer unique weapon variants.
- Safe Codes: In certain missions, finding codes allows you to open safes containing valuable gear or intel.
- Easter Eggs: Hidden references or interactive elements that pay homage to previous Call of Duty titles or pop culture.