Keep character in case of death
Save and quit the game. Find the save game file for your player, named in format <character name>.svg in the "savedg" folder. Copy it to the Windows Desktop and load the game. If done correctly, you should have one copy of the save file on your desktop and one in the "savedg" folder. The desktop copy is the backup and should be copied to the "savedg" file after you die in order to continue the game. Note: Update the backup copy often.
When you die, if you saved before, the game erases that save file so you cannot restore it. When you save a game, go into "adom_dat" folder then enter the saved games. Copy your save file to another folder. When you die, the file in the original folder is destroyed, but not the other one. Copy it back into the original folder and continue from where you left off.
Duplicate items
Go into the hamlet and drop the items you want to duplicate. Leave the hamlet and exit the game. Look in the "adom_dat" folder and go into the "temp dat" folder. There will be two files there. Copy them to another folder then resume the game go back into the hamlet. Once there, get your items and leave again. Copy the temp files back into the original directory (answer "Yes" to overwrite all). Then, go back into the hamlet and the items will be laying there again. You can also transfer items to other characters by doing this.