Successfully complete the game under the hard difficulty to unlock the Red Dragon Armor for Zanek and be able to use the Silver Sword. You can get the Red Dragon Armor after you complete the tenth chapter under the Hard difficulty setting. Go into "Upgrades" and then into the armor upgrade for Zanek. It will appear directly below the mithril armor. The Silver Sword will already be equipped and cannot be upgraded.
Into The Underdark: Unlimited gold and experience
The level "Into The Underdark" has unlimited experience and gold. When you get to the part of the stage with the ice barrier and wizards, switch to Zhai and use the shadows on the right side of the bridge to sneak attack enemies that appear from the right tunnel. You can do this as long as desired. Zhai steals gold from enemies when invisible. Get as many kills as possible. When satisfied, continue on to fight Cireka. Only kill the wizards that fire missiles at you. The large slow moving bombs go directly for the character you are currently playing. An unlimited number of enemies will flow from the portal. Kill them and get your characters' hero meters up. When full, use it repeatedly. You must do this at least twenty times for decent experience. The more times you do your team attack, the higher the experience multiplier at the end of the level.
Picture gallery
Successfully complete the following levels to unlock the corresponding picture in the gallery.
Attack at Cedarleaf: Cedarleaf
Gemspark: Concept Art
Into the Underdark: Githyanki Outpost
Stand at Mithral Hall: Mithral
The Dragon's Lair: Dragon
The Jungles of Chult: Chult Jungle
The Lord of Chaos: Limbo
The Wizard's Tower: Wizards Tower
The Yuan-Ti Temple: Chult Temple
War in Damara: Battlefield
Secret books
Successfully complete the following levels to unlock the corresponding secret book.
Attack at Cedarleaf: Zhai's Past
The Wizard's Tower: Khelben's Letter
The Jungles of Chult: Illius' Youth
The Yuan-Ti Temple: Nesme's Fall
Stand at Mithral Hall: Cireka's Vow Drizzt's Journal
Into the Underdark: Ygorl And The Dragon