There is no way of telling exactly, but often you can get keys from treasure chests (or smaller boxes or containers) or by pickpocketing/looting them off guards or other people who might have access to the area you wish to enter.
When you queue for a random heroic, you don't need to unlock the Burning Crusade heroic dungeons. However, if you want to enter on your own (or with a group on your own) then you will need to buy the corresponding key from a rep vendor. Each faction sells one key, obtainable at Honored or higher reputation Honor Hold/Thrallmar have the key for the Hellfire Dungeons in Hellfire Peninsula Cenarion Expedition has the key for the Coilfang Reservoir Dungeons in Zangarmarsh Lower City has the key for the Auchindoun Dungeons in Terokkar Forest Sha'tar have the key for the Tempest Keep Dungeons in Netherstorm
You no longer need a Beta Key. Heroes of Newerth is free to play.
in some dungeons there will be doors you use the key on the doors while facing them
they are on the floors of higher leveled dungeons.
Use the walkthrough.
key?
gG74
roll of project sales officer
You can register hon with a beta key. You can find a beta key at sharpmethod.com
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Get the key on bingo highway.