While playing a game, hold L1 + R2 + Left + Triangle, then press Start. A cheat menu with "Invincibility", "Level Warp" options will now be unlocked.
While playing a game, hold L1 + R2 + R3 + Left, then press Start. Your character will now be at level 20 and have access to all feats. Your character will also have level 1 feats on all class-dependent feats and 75,000 more gold pieces.
Play as Drizzt
At the main menu, hold L1 + R1 then press X + Triangle. Alternatively, successfully complete the game on the extreme difficulty setting to unlock Drizzt.
Save the game, then drop the items to be duplicated from the inventory of your current character. Press Start and choose change your character. Import your character from the previously saved game. The game will bring in your character with all items in inventory at the time of your save, and allow you to collect the duplicates that are on the ground.
Resurrection in multi-player mode
If a player dies during multi-player mode, have the surviving player go the previous save point. Then, press Square (Use) repeatedly with the deceased player's controller. The character will be resurrected with all items, but at half hit points.
Successfully complete the game on any difficulty setting to unlock gauntlet mode.
Successfully complete gauntlet mode to unlock the extreme difficulty setting.