However, in Single Player the death penalty will not take away all your gold. No gold is taken from the Stash and 500 gold per character level is exempt from the death penalty. For example, if a level 10 Single Player character with 5,000 gold dies, no gold is lost.
As an additional death penalty, in Nightmare and Hell difficulty levels your character loses some experience, but will not drop down to a lower character level.
For information on Hardcore characters, games, and their death penalty check the Hardcore page.