Caesar III Cheats (PC)

While building street, plaza, gardens, etc., put where you want to end building close to
the right build buttons.  Hold down the mouse while you are building a street, etc. and
drag the mouse off the screen onto one of the build buttons.  Your money stays the same. 
You must build one thing for real before you use the north, south, east, west buttons or
it will become disfigured. Works great on streets, plazas, gardens, but not houses.

Enable cheat mode. then press [al + C during game.
  (note: cheat only works if you have less than 5,000 denarii.)

Need more money? Want to skip a certain mission? Then here you go! 

  In order to enable the cheats you must right click on a Well, then press ALT K. Now, to
achieve instant victory, hit ALT V. To give yourself more money, hit ALT C (this will only
work if you have less than 5,000 DN).

Go to your sierracaesar3 (or something else?) look for any ???. ini files edit them. One
of the files has this as text : Bla, Bla, Bla
  read everything above
  dig
  statue
  ?
  if you read it you should find the letter of the costs of building a structure like
this:
  ?
  250 change it into -250000
  Instead of paying it you receive it!

Right-click on a well and press alt + k, then enter alt + v and press the back button in
the window.

Place barracks in far-removed places.

Place a barrack in a location so it is not connected to roads, and thus not accessible to
workers. Quickly place additional barracks in similar locations to quickly produce
soldiers.

Enable cheat mode. then press [al +V during game

Right click on a well and press [al + K to activate cheat mode.

Right-click on a well and press alt + k, then enter alt + c press the back button in the
window.

Note: This procedure involves editing a game file; create a backup copy of the file before
proceeding. Use a text editor to edit the "c3_model" file in the game directory. By
editing this file, the cost of objects may be changed (lower or free), improve
desirability, and lower the number of people a building employs.