- For the location of the locks and their required codes, see Codes.
Number Locks are one of the more heavily guarded locks, as they were used to get into areas not meant for the general public. When the player comes across one, it is locked and needs a code to open it. The codes can usually be found in audio diaries or written somewhere in Rapture. Most codes are given before encountering a safe, but some are given as far ahead as four levels into the game from where the lock was first encountered. Once opened, these locks provide access to rooms and areas with various loot or hidden items.
In BioShock, the player has the option of hacking or buying out the number lock, which negates the need to find the code.
- The Alarm Expert, Hacking Expert and Safecracker Tonic lines will reduce the number of Alarm Tiles when hacking.
- The Focused Hacker, Hacking Expert and Safecracker Tonic lines will reduce the number of Overload Tiles when hacking.
- The Safecracker line of Tonics will increase the number of Resistor Tiles and decrease the number of Acceleration Tiles.
- The Speedy Hacker and Security Expert line of Tonics will slow down the flow of the liquid when hacking.
- The Hacker's Delight line of Tonics will restore a part or even the totality of the player's Health and EVE after completing a successful hack.
In BioShock 2, the player can no longer hack or buy out number locks. Each one must be opened with the proper code. However, this is made easier because the game will automatically remember and show the code as a note during the key lock sequence if the player has previously seen it in the environment or heard it in an audio diary.
Only one number lock is present in BioShock Infinite in the Grand Central Depot.
It is needed to progress in the story and can only be interacted by finding the combination nearby.