All the battlefield keys that you need you find in the main parts of the game. Some may be lying on the ground right out in the open. Others may be on an enemy you must kill, and others will be well hidden. I think if you don't find a key, but find the next one, then it will allow you to access the one you missed. In other words if you miss the key for dungeon 2, but find the key for dungeon 3, then that higher level key will allow you to access the lower level dungeon. I don't know for sure because so far I have found them all. You experts out there please correct me if I am wrong.
And "Tired Warrior", why are you always tired???? <img src="/ubbthreads/images/graemlins/sleepey.gif" alt="" />