What is Adventure mode?

Adventure mode is a feature from Epic Loot that adds a new trader window. (All screenshots were taken with the UI mod Auga, by RandyKnapp)

Secret Stash:

The secret stash is the the tab where you will be able to purchase enchanting materials and a Andvaranaut. The Andvaranaut is a utility item similar to the wishbone you get from Bone Mass. This powerful ring helps the player locate the treasure chest after purchasing a treasure map.

Gamble:

The gamble tab is where you can spend your hard earned gold for an item with a random rarity. You can also buy rare, epic, or legendary items for gold and one of three special currency, the Iron token, the Gold token, or the forest token.

Treasure Maps:

Treasure maps are purchasable quests that give you an area on the map to go and find a Treasure Chest. In those treasure chests you can find gear ranging in quality and forest tokens. (These rewards can be changed in the server config)

Bounties:

Bounties are quests to do the obvious, you go and slay the bounty that you have accepted for gold, iron tokens, gold tokens, AND GLORY! Bounties can be gated in the configs. Unlimited, BossKillUnlocksCurrentBiomeBounties, BossKillUnlocksNextBiomeBounties.

If you are on a server you must have Epic Loot and Extended Item Data Framework installed client side and server side in order to complete bounties.