The Hak trick

The "Hak Trick"

This is a recovery method that can often be used to salvage failed save games, update in-game data via save game, or provide bug fixes mid-play, obviating the need for the player to start the game over again from the beginning if there's a problem. It's based on the fact that a save game and a hak file share the same data structure.

1. Locate your saved game. This will be under the 'saves' folder of your NWN install, often C:\Neverwinter Nights\saves. The subfolder containing the saved game will have the same name as the name you supplied when you saved it.
2. Within the saved game folder there should be a file whose name is the same as the module you're playing, postfixed with .sav.  Copy that file somewhere safe to use as a backup in case you screw something up.
3. Rename the save game file to 'x.hak'.  Don't just change the file extension to .hak, because in order to edit it in the following step, the name will need to be at most 16 characters long and many module names are longer than that.
4. Open x.hak in the hak file editor, nwhak.exe, normally located in your NWN utils folder.
5. As long as you have it open in the hak file editor, you can do all sorts of neat stuff, like adding or replacing scripts, exporting or updating module information as a snapshot of your current game in progress. You can even re-initialise entire areas, all whilst conserving the integrity of the rest of the module, including your savegame state.
   Note: Do not change anything else, such as the text entries in the top few lines of the hak editor.
6. Once you've finished doing what you need to do, save x.hak and exit nwhak.
7. Rename x.hak back to the name it was before. Please remember to do this ; you must remember to do this, or be prepared to cry yourself to sleep later on, as NWN will silently and callously delete any files it finds in its savegame tree whose names don't correspond to the required format (but see step 2, above).
8. Fire up NWN and pick up where you left off.

Voilà.