So I am an Age of Empires whore. Information whore. AOE3 whore. Total War whore.. I'm a whore all around apparently. So lets talk about AOE3 and 'helping' your explorer out. Most people don't realize the strategic and tactical value of this unit.. but if you are a smart player, you will!
Go to the folder containing all of the AOE 3 stuff. Open the folder called data. Right click proto.xml and go to open with and choose notepad. Press CTRL and F. Type in the name of the unit you want to find, e.g.: Explorer. Scroll down until you see all kinds of things starting with . Anywhere in that area, make a new column and press CTRL and TAB twice. Type:
Invulnerable
and on another line type:
DoNotDieAtZeroHitpoints
Save the file then open AOE 3. Send your explorer into battle. HE WILL NEVER DIE!
Note: This secret affects enemy units as well as your own.
Another Note: If you go all crazy and try to type stupid stuff like PWNALLTHEM!!! and the game crashes, it is enitrely your fault.