XBOX & PS2:

Cheat: Mission Select
When entering Sam Fisher’s name, replace it with !lamaudite! instead to pick a mission. Note that this only works for the Xbox version of Splinter Cell!

Cheat: Training Stage Secret
In the Training Stage, after you complete the task of looking at the lights, you can go over to the left or right of where you are. You will be above the lights to find two doors. On the right is a door that leads to a room where a lock pick is sitting on the shelf beside the door. You can use this to get into the door that is located just beside the door leading to the covert-ops section of the training.

After getting in this door and getting the keypad code (the code is 5656) you can then go on the left and get into the doorway on the left of the start of the level. Through this door is two rooms. In the last room is Anna Gromsdottir. You can talk to her about different things, but DON’T hit her because you will be fired!

Cheat: Keypad Codes
Below are a list of keypad codes in the game, sorted by applicable mission, so you don’t have to figure them out yourself.

Mission 1 - Police Station

Mission 5 - Kalinatek

Mission 8 - Chinese Embassy, Part II

Mission 9 - Presidential Palace