Item Binding, "Bound", or "Soul-Bound" refers to the ability of an item (Armor or Weapon) to attach itself to the Soul of its owner or wearer. Once Bound the item cannot be traded to another player or sold in the Auction House. Bound items CAN be sold to a Merchant (unless the item is labeled "Cannot be sold").
- Bind on Pickup/Bound - (Item Template has |bound=y) This item becomes Bound when you find or receive it. You may sell it to a Merchant but may not transfer it to another player (unless Unbound).
- Bind on Equip/Binds when equipped - (Item Template has |binds=y) This item becomes Bound when you equip it. Until then you may trade it to another player or sell it in the Auction House.
Most Common items below level 30 are not Bound when used and may be traded or given to other characters even after use. There are a very few items in the game of higher quality that do not bind on pickup or when first used. One of the very few are the 10 Good Accessories rewarded from the quests of the Vahtos' Apprentice quest series.
The Bound status of an item may be changed by using a 
Bind Lifter.
- Bind Lifter (Basic) - Can Unbind an item that was originally Bind on Equip
- Advanced Bind Lifter - Can Unbind anything including items that were originally Bind on Pickup