Key

General
Keys are used to unlock chests across the world.

Keys are named (more or less obviously) after the geographic region where they are bought or found (eg. Ascalonian Key for Ascalon) and can only open chests from that region. For example Ascalonian Keys will only open Ascalonian Chests, Krytan Keys will open Krytan Chests and so forth. The value of keys increase as one progresses in the game, as does the value of the items found in the chests they unlock.

Keys of the same type will stack.

Note: There are no keys or locked chests in pre-Searing.

Usage
Keys may only be used once, meaning players will have to gamble that the items found inside a particular chest will either be useful to them, or have a higher resale value than the key. Because of this risk, when you click on a chest, a confirmation message will popup asking whether you are sure that you want to use a key to open it.

Each member of an exploring party will have to use their own key to open each chest, however, the items found from chests are not shared across the party. A chest opened by a player cannot be opened again by the same player.

Note: Currently, the rarity of items produced by the chests is consistent for the same chest. i.e. If a chest produces a purple item for the first player who opened it, it will produce purple for all who open it afterwards.

Acquisition

 * Bought from merchants in the same region.
 * Random Loot from monsters of the same region. This includes monsters of the region which are encountered elsewhere. For example, Mahgo Hydras encountered in the Burning Forest of the Fissure of Woe will drop Darkstone keys (of the Ring of Fire Islands where they are originally from) instead of Obsidian keys of the Fissure (where they are). Likewise, Banshees encountered in the Fissure will drop Phantom keys of the Underworld, where they come from.

Value of Loot
While the keys are guaranteed to produce purple items or gold items, it is not guaranteed that these items will be perfect or have maximum statistics. In general, the key is worth more than the item produced from the chest if the item was sold back to the merchant. For example, a Shiverpeak Key is sold for 600 gold but on average produces items that are worth 200-300 gold at the merchant. The real value is that identifying the item might unlock upgrades or that the item would have great statistics and thus sell for multiple platinum to other players in trade.

The value of items produced from chests is directly proportional to the value of the keys. Gold items found unlocked by Obsidian Keys will be near perfect in their statistics, while those unlocked by a Krytan Key may not even have maximum damage.

The Keys themselves can be sold for half their price to all merchants.