How do I play a LAN multiplayer battle in Rome: Total War - Gold Edition?

Playing a LAN multiplayer battle in Rome: Total War - Gold Edition is slightly different depending on whether you wish to host the battle, or simply join it.

To host a game:

Double-click on the Rome: Total War - Gold Edition application icon. By default this is to be found in the Applications folder on your computer's hard drive.
The Rome: Total War - Gold Edition pre-game Options window will appear. Select either Rome: Total War or Rome: Total War - Barbarian Invasion from the Select Game drop-down menu.
Click on the Play button. The game will launch.
From the Main Menu, select Multiplayer.
From the Multiplayer menu, select LAN Battles.
A dialog will appear prompting you to enter a player name. Enter your name, then click on the Tick button.
The Lobby screen will appear. Select the Host a New Game button.
The Host Game screen will appear, from which you can adjust your battle settings. You must enter a valid Game Name before you can continue.
Select Host Custom Battle. If you selected Rome: Total War in Step 2, you will also be able to select Host Historical Battle.
The screens that follow on allow you to customise your battle, including choosing your army. When you are happy with your settings on each screen, click on the Continue button (golden arrow) to proceed to the next screen.
From the Customise Army screen (in a custom battle) or the Choose an Army screen (in a historical battle), click on the Continue button (golden arrow) to indicate that you are ready.
The game will begin once all the players have indicated that they are ready.

To join a game:

Double-click on the Rome: Total War - Gold Edition application icon. By default this is to be found in the Applications folder on your computer's hard drive.
The Rome: Total War - Gold Edition pre-game Options window will appear. Select either Rome: Total War or Rome: Total War - Barbarian Invasion from the Select Game drop-down menu. You must select the same option as that selected by the host.
Click on the Play button. The game will launch.
From the Main Menu, select Multiplayer.
From the Multiplayer menu, select LAN Battles.
A dialog will appear prompting you to enter a player name. Enter your name, then click on the Tick button.
The Lobby screen will appear with a list of available games. Select the game you wish to join, and click on the Join Selected Game button.
The screens that follow on enable you to choose your faction and army. When you are happy with your settings on each screen, click on the Continue button (golden arrow) to proceed to the next screen.
From the Customise Army screen (in a custom battle) or the Choose an Army screen (in a historical battle), click on the Continue button (golden arrow) to indicate that you are ready.
The game will begin once all the players have indicated that they are ready.