Bind on Equip
From Diablo Wiki
Bind on Equip items are designed so that they can only be used by the character that first equips them. They can be traded freely when found, but once any character equips them, that's it. They item can never again be traded, or passed between characters even on the same account. BoE is commonly-used in RPGs, especially in MMORPGs, to prevent item inflation over time, by removing items from the economy.
- There is no item binding of any kind in Diablo III.
 BoE in Diablo III
Binding isn't really substantial in making a viable economy, but it is really good at establishing item prestige. Which is how it's used in WoW.
We expect salvaging to be compelling enough to remove a good percentage of the most valuable items from the economy. High end components obtained from salvaging high end items are needed for high end crafting and enhancement.We're not promising anything on patch content, but we also feel that keeping up on introducing new items consistently will keep it from being possible for a glut of the best items from building as 'the best' can be a constantly moving target.
The Diablo 3 team also considered BoA, which would have limited items to the account that found them. This would have allowed a player to twink the item between his characters, but not to trade it into the open economy.
 Blizzard Comments
- Jay Wilson: We have no “Soulbound” or bind-on-pickup, except for quest items. We do have bind-on-equip for the highest end items in the game. We targeted, roughly, any item above level 85. These we will do as bind-on-equip. The reason for this is that we want people to be able to trade them, but we also want to remove the high-end items from the economy. One of the greatest ways that you can do that is with bind-on-equip. What we don't want is to have a situation where you find something on the ground like, “Oh, man. This would be a perfect weapon for my Monk. Oh, but I just picked it up and now it's on the wrong character.” We don't want that at all.
- Most of our focus on Diablo 3 is as a trading game. So, if you take trading out of the item space, you ruin the core of the game. Finding a really great item that is not for you is still a great event because it means you have a bartering tool to get the item that you do want. We definitely want to make sure that that still exists.
Bashiok addressed this issue during a mini-interview posted as part of Blizzcast #13, in February 2010. 
- Bashiok: Maybe. It sounds kind of cool. So I asked Jay and some of the other designers about this actually because I wasn’t sure, but Jay’s response was “That sounds awesome!” And he likes things that are awesome. Which is a very Jay Wilson quote. But there could be economic reasons that we don’t do that, there could be gameplay reasons we don’t do that. It’s probably too early to say, but that sounds cool so we’ll have to see.
Bashiok elaborated on this later that same day, when a fan pointed out that BoA could lead to stagnation in the economy, if every account eventually had several of the best items that players could pass around between their different characters. 
- Totally, which is why I said “But there could be economic reasons that we don’t do that.”
- It would probably stagnate the economy… UNLESS, there are other systems in place that could make it attractive for players to essentially destroy their BoAs. So I don’t think it’s without solution at least, but it could get sticky if not balanced or pulled off just right.
- Anyway, we’re not really seriously considering BoA items at this point in time.
Binding was finally ruled out in April 2011, by Jay Wilson in an interview with Diablo3.cc. 
- August 2009: Game Director Interview by G4TV.com.
- February 2010: Bashiok on Blizzcast #13.
- February 2010: Bashiok forum post.
|Items of Diablo III  Item Basics Normal Items Legendary Armor I Legendary Armor II Legendary Weapons 1h Legendary Weapons 2h Item Sets|
|Item Basics||Item Modifiers||Inventory||Artisans||Merchants||Miscellaneous |
|Armor - Class-Specific||Weapons - Class-Specific||Crafting Items||Other Items |
|| • Blacksmith Plans
|Waist||Wrists & Hands||Legs & Feet||Head |
|| Voodoo Masks - WD|
| Chest Armor
|| Amulets cont.
|| Rings cont.
40) Puzzle Ring
|| Sources - Wiz|
|| Fist Weapons - Monk
|| Mighty Weapons - Barb|
|| Daibos - Monk
|| Bows |
|Item Sets |