Duplicate items:
Save the game and then drop the items to be duplicated. Press Start and choose "change character". Then import your previously saved character.

Play as Drizzt:
Start a new game with any character. When the game is loading hold L1+L2+R1+R2.

Cheat menu:
During the game hold L1+R2+Left+Triangle and press Start.

Super character:
During the game hold L1+R2+R3+Left and then press Start.

Gauntlet mode:
Complete the game on any difficulty setting successfully.

Extreme mode:
Complete gauntlet mode successfully.

Play as Drizzt Do'Undren:
Complete extreme mode successfully to enable Drizzt Do'Undren in a new game.