Description
Each of the 14 main Black Ops missions contains three hidden intels, making for a grand total of 42. The individual intels resemble traditional rectangular recording devices with two cassette reels. The intels do not flash or stand out from the background, so it can be easy to overlook them during the game's intense action.
Achievement
Collecting all 42 intels earns the Closer Analysis achievement trophy. While the accomplishment doesn't give the player any in-game advantage, the achievement is worth 15 points towards your Xbox 360 Live gamerscore and awards a trophy icon depicting an unraveling cassette reel. The game does contain a cheat code that will unlock all 42 intels, but using the cheat prohibits winning the achievement trophy.
Intelligence
Accessing the intel section form the main menu provides more information about the specific missions, including each mission's background and the biographical information for the people involved. Some lines within the typed reports will be blacked out to protect classified information. Finding the 42 hidden intels removes the documents' black bars, exposing all critical details. Reading the reports will even offer information teasing the game's sequel, "Call of Duty: Black Ops 2."
Tips
Finding the 42 intel recording devices takes a keen eye. While they're often out in the open, sitting atop desks or nightstands and racks, the intel devices may blend in with the surroundings, particularly when the bullets are flying. Closets, sheds and more discreet hiding places may also hold intel, so take your time and investigate all possibilities. The "Redemption" mission contains three of the most difficult devices to find. The first is wedged beneath the door of a cargo container, while the second is amongst the junk beneath the control room's table and the third is hidden underneath a control panel in the underwater base.