You can use the same in-game code again, but only one time for each game.
For example, if you purchased a HeroMart item that has in-game items for more than one Artix Game, such as AdventureQuest Worlds and DragonFable, if you redeem your code for AQWorlds but not for DragonFable, you can go back later and redeem the code again for DragonFable.
If you already redeemed your code for one game, you cannot redeem it again and can only receive one specific in-game item once.
Codes cannot be given away as a gift if they have already been redeemed for at least one of your accounts.