The wiki lists the other difficulty modes, as well:
Tactician Mode
- NPCs get +20% HP.
- Currently known as Hardcore Mode, this mode gives most creatures in the game additional skills & abilities, including bosses.
[there are also changes to the world, such as an extra explosive barrel in the orc fight at the start of the game, which the orcs can use against the players, if they aren't paying attention]
Honor Mode
- NPCs get +20% HP.
- The user has only 1 save slot, so every time they save / quicksave / autosave, the savegame is overwritten. If a character dies (PC, companion, henchman) the game autosaves.