In the overworld map (not during battles), press the Console key (Backspace by default) and type one of the commands as listed. Then press Enter.
If the code includes (firstname), replace the whole parenthesis with the first name of the character you want the code to affect. If the code contains (ItemName), replace the parenthesis with the name of the item as shown in your inventory, capitalised exactly the same way, but with NO SPACES.
If the code contains a #, replace it with whatever number you want.
Cheat Code Effect
setmorale (firstname) # – Change a certain character’s morale.
illuminati – Display all plot variables.
devmode – Enable teleportation with the T key.
giveitem (ItemName) # – Give yourself a certain inventory item (# is optional).
giveequipment # – Give yourself more equipment.
givexp # – Give yourself more experience.
giveherbs # – Give yourself more herbs.
givemeat # – Give yourself more meat.
givemedicine # – Give yourself more medicine.
givemetal # – Give yourself more metal.
giveoil # – Give yourself more oil.
giverations # – Give yourself more rations.
giverope # – Give yourself more rope.
givevaluables # – Give yourself more valuables.
givewood # – Give yourself more wood.
smite (firstname) – Injure a certain character.
thespanishinquisition – Injure all followers.
kill (firstname) – Kill a certain follower.
vontrier – Release camera from the player character.
remove (firstname) – Remove a certain follower from your party.
tordenskjold – Restore all injured followers to health.
return (firstname) – Return an absent follower to your party.