Sid Meier's Civilization III: Complete Cheats

When you go to save, name the save ''multi'' without the quotes.

This allows you to see the map and you can change what other civs are producing, among other things. (Does not work with patch 1.21 or later)

When another tribe ask you to trade something with them, they will often try and cheat you. Instead of accepting straigh away, propose a counter offer. Once the counter offer screen comes up, click the items they are offering so that the 'What will you give me for this' option comes up, then click that. Now they will offer a list of things that (very often) weren't there in the initial trade.

Normally the game would not allow the player to speed up the building of Wonders through hurry methods such as pay citizens and force labour. But it is possible to get around this by first selecting a building option (preferably one with a high production cost), speed up that project using a hurry method, then switch to the Wonder of your choice. Notice that the production shields brought from before the switching is still in place. This is fixed in version 1.29f.

To have Elvis display as the king units in regicide mode, change your computer's date to January 8th, 2004.

Normally, when playing a game with King units (Regicide, Mass Regicide, etc.), , the units are the leader of the nation you are playing (America would have Abraham Lincoln, England has Queen Elizabeth, etc.).
On Elvis birthday, January 8th, play a game with King units and all the King units will turn into Elvis.