Press the Right Mouse Button on a well. Press [Alt] + K, then enter one of the following codes to activate the corresponding cheat function. Note: Some versions of the game require [Ctrl] to be pressed in addition to [Alt].
[ALT] + V: Instant Victory
[ALT] + C: More Cash (If Less Than 5000Dn)
Custom Game
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.
Quick Soldiers
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.
Mystery Goods
If a cart pusher gets to a warehouse to export some goods when there is none, he will still get a load and they will pay for it.
Use this cheat when you get the option of going into the Senate:
Click the Emperor icon in the Senate. Give yourself a wage of 500 denarii (Caesar's wage). After a few months, when you accumulate about 3000, go to the same screen and press the "Give to city button".
Click the "all" button in the dialog. Then press the "give" button.
Notice, now you don't have any savings at all. Nevermind ;)
Press the "Give to city" button again.
WARNING: DO NOT PRESS THE "ALL" BUTTON AGAIN OR YOU'll GET YOURSELF INTO TROUBLE!!
The quantity of money to give to the city is the money you gave before. So you just press "give" button again, and your savings go in minus, but who cares 'bout them anyway :)
So just keep repeating this and you'll have a fortune.
And yes, don't be afraid to turn off the Senate screen. You can turn it off, and return to it later to give yourself more money.