Safes, door locks, toolboxes, and container keypads in the Call of Duty: Modern Warfare III campaign are spread across four missions. Some codes are required to progress the main story, while others lead to optional loot areas or collectibles.
In the "Following Orders" mission, players can find a locked toolbox in the room on the right while searching civilian homes; the code is 214, though the lock can also be shot open. Inside is a note and a contraband item, with the code clue coming from a Baekseolgi-Tteok recipe note. The "Assassins" mission has three story-critical doors that must be opened, with codes 5523, 7632, and 9103. Players can hear the numbers over the radio when approaching the keypads, and enabling subtitles helps avoid missing them.
The "Stranded" mission features six keypads leading to optional loot areas. The codes for the base camp, the cliff near the camp, the south side of the jamming station, the large sign, the southeastern village, and the small island are 0024, 0600, 8609, 1234, 0078, and 6789, respectively. Nearby notes provide number sequences, but players can also deduce the codes from clues.
In the "Escape" mission, the safe is located near the area Ghost mentions as being close to the garage, with the code clue hidden in another unlocked side room. Entering 8410 allows you to retrieve Gaz's Dog.exe tags and unlock the "Never Forgotten" trophy or achievement.