Well, there is this app called Cheat Engine, which can tap into the memory of a running game process and lock or overwrite values stored at specific addresses. Most often people use it to, obviously, cheat. If, for example, you isolate and identify memory address that stores health points or ammo count or any other variable, then you can set it to any value you want or lock it to prevent it from being changed by the game. When you have a collection of these memory pointers, you can store them in a table and then load it automatically when you run the game via cheat engine, or save it to a file and share the table with other people, so they can do the same.