The games of the Marathon Trilogy use the "save point" concept for game saves. This requires the player to reach a specific map location before the game can be saved. If the player is killed before reaching and activating the next save point, all progress since the previous save point will be lost.
Description[]
Specific Terminals known as "pattern buffers" serve as save points in the Marathon series. After reaching and activating these terminals, the player can save game progress as a checkpoint for their current session and as a way to restart the game at that point in a future session. The term "pattern buffer" implies that the terminal is buffering (saving) the Cyborg's molecular/atomic pattern so that it can be reconstructed later.
Master Chief Mode[]
In the iOS versions of the games, an add-on called "Master Chief Mode" allows the game to be saved at any point, without the need for a pattern buffer.