Vegita submitted this

If you're having trouble defeating an enemy keeper, there's an AI bug you can exploit that makes your job far easier. If you have the patience, simply wait and continue to build up your dungeon, monsters, and fortifications (the last so your enemies don't come looking for you). The computer never mines gold; it simply uses what it starts with. Wait long enough, and it will run out (take care that the same does not happen to you); when that happens it's monsters tend to desert. After a while, all that stands in your way is an empty dungeon and a few measly imps.

On another note, you can see gold veins at the very beginning of the stage. While they look the same from the overall map, gems can also be seen early. It is a good idea to look through the map early on, to see if there are any gems on the board. The knowledge can be very useful for your playing strategy.

However Jeff Stewart tends to disagree:

"It's not true! Don't think that the enemy keeper won't mine gold! Yes, it's true that sometimes the AI doesn't quite understand mining, but if there are gems to be found in a level, you can rest assured that eventually, the enemy WILL get to them.

But exploit the computer's slowness! If you can grab all (or most of) the gold before the computer does, then yes, you have a good chance of seeing an enemy keeper with nothing but a few imps to boast about.

D&D - here?
(Doors 'n' Disease)