Some people would like to be able to make a backup copy of their character. In order to make a decent implementation of this, your author would like to find out what exactly these people mean by that.

When I play rogue (in my ideal world)...
I am a "purist" - when I die, I start over from scratch
I am a "purist" - but I would like the game to auto-save so that a crash will not kill me
I sometimes copy my current character before doing something 'dangerous'
I copy the ongoing game regularly (overwriting the old copy so that only one backup exists)
I have multiple snapshots of my current game
I have multiple snapshots of the past several games
Forget about 'save', I want to be able to 'undo'

It is a good idea to stay consistent with a role-playing model. This game is not based on the world of Paranoia, but the world of Dungeons and, er, critters; there, restoring life to the dead is a difficult task so there should be a price for restoring from a copy. What would be the most "realistic" penalty?

When I restore from a copy
Subtract from my gold. It is worth paying, for a resurrection spell.
Subtract from my max HP. Being dead is bad for one's constitution.
Subtract from my strength. I feel weak after time in Intensive Care.
Subtract from my experience. I lost recent memories due to head injury.
A character restored from a copy should be treated like a wizard-mode character: it should not appear in the high score list.
Yo, I'm going to download the source, disable the penalty, and compile my own version.
Result