In the middle of a quest, if you use a hero save and reload the save, you will start at the beginning of the quest as if you had never begun, and you will retain all items that you obtained during the last run of the quest. This is especially useful in the Arena, where vast amounts of money can be made if used right. This exploit can also be used to get infinite silver keys, potions, etc if used during missions. If used too many times, this exploit can cause damage to your saved game.