The Dungeons of Forgotten Heroes is currently not available and based on the last information received it will not be available anymore in the future either.
After confirming the participation to the Dungeons of Forgotten Heroes you will start off in the shop of the instance. As known by mages from battlefield of equals, you start off completely naked and with empty slots and backpack. The only thing you will have in your backpack to start off with is 25pcs. of Pots of Dumplings, to restore your HP fully between fights.
First thing to do in the instance is buying a potion for 1g, which will directly morph you into the character you will be playing for that specific instance.
Leaving your base you will find a lot of rooms with monsters roaming around. These monsters are fairly easy to kill, however they get stronger the further away you get from either of the bases. They will drop a random amount of Forgotten Heroes Tokens (usually between 1 and 10pcs and up to 30pcs for the more aggressive and stronger ones). These can be spent in both shops in the instance. The first one you can access by going back to the base, entering the same shop in which you started off.
In said shop you can purchase elixirs to increase yours stats, more Pots of Dumplings and Summons. The price for potions range anywhere between 100 to 900 tokens, depending on how strong their effect is. Pots of Dumplings can be bought for simply 1 token and the summons will cost you 15 tokens, which is quite a low amount but as can be expected from the price the summons are rather weak.
The other shop is located in the middle of the instance, so you will likely meet members of the other team while going there. This shop contains cover armor which does give stats though, again depending on the type and amount of stats you get for an item are the prices. These range anywhere from 250 to 1500 tokens.
Now on to the classes you can choose to play as. Several players can choose to play as the same class, however it is recommended to mix up the different classes. As for example the Desert Scout can Lost Soul its enemies, preventing them from resurrecting. The only way to remove this is if the team has someone playing as a Servant of the Brotherhood, who can use a Deliverance Thurible to reattach ones soul.
For an overview of what each class does, please refer to the Game Library for now. Note that the Dungeons of Forgotten Heroes is still in beta testing, thus it most likely still contains some bugs. Please take it easy, enjoy the new experience and leave Feedback in the Game Forum Thread.