Die Hard: Nakatomi Plaza Codes -

God mode:
Note: This procedure involves editing a game file; create a backup copy of the file before proceeding. Use a text editor to edit the "autoexec.cfg" file in the game folder. Change the "PlayerTakeDamage 1" entry to "PlayerTakeDamage 0".

No clipping:
Note: This procedure involves editing a game file; create a backup copy of the file before proceeding. Use a text editor to edit the "autoexec.cfg" file in the game folder. Change the "PlayerClip 0" entry to "PlayerClip 1".

Invincible enemies:
Note: This procedure involves editing a game file; create a backup copy of the file before proceeding. Use a text editor to edit the "autoexec.cfg" file in the game folder. Change the "AITakeDamage 1" entry to "AITakeDamage 0".

Enemies take more damage:
Note: This procedure involves editing a game file; create a backup copy of the file before proceeding. Use a text editor to edit the "autoexec.cfg" file in the game folder. Change the "AITakeDamage 1" entry to "AITakeDamage 99".