Stonekeep cheat codes:
Invincibility
While playing, pick up a skull from your inventory and
press F9. Note that your health will drop when you take
damage, but it will never drop below 1.

Dagger of Penetration
Start a new game. Before going down the first flight of
stairs, find the lever on the wall next to the stairs.
Pull it Up, Down, then Up again. After that, check all
of the inner walls on the square shaped hallway that you
found the giant ants in.
Eventually, you will find a secret compartment with a
lever in it. Pull the lever Down and you'll hear a sound.
Check around the hallway for a new passage. You will find
three grenades and, (if you search the walls) a secret
compartment with the Dagger of Penetration -- the second
best dagger in the game!

Build Up Status
There are two ways to build up a character’s status. One way
is to go to the Dwarf Clan Hall and whack the onyx stone
beside the blacksmith. The other way is to use invincibility
and beat on Ettin, the two-headed giant.