A new update for Civilization 3 will allow players to engage in multiplayer on Valve's Steam platform.
Last Spring, GameSpy parent Glu discontinued online support for Civilization 3 and a huge number of other titles. Firaxis and 2K Games are saying that the update will work with all Steam copies of the game, but will still require players to submit a support request to access the multiplayer content.
The multiplayer features will work exactly the same as before, only the "Direct IP" option will be missing. It's not supported by Steam and there are no plans to revive it.
All of your current save data will remain intact and should not suffer as a result of the update.
Here's to a great future for Civilization 3.
