BF2:Co-op mode
From BattleWiki
Online Co-op
Start a singleplayer game, have a friend connect to your IP manually.
For clarification: the connect to IP command is under the multiplayer menu, on the center-left hand side.
Offline Co-op
If you do not have Internet access to get to the "Join IP" button, there's hope for you.
The host needs to first create a local server. The map and game type (conquest) do not matter.
Once the server has been created, have the co-op participants go to the server browser. Look for the newly-created server. Do not connect!
When the server is shown in the browser, have the host disconnect the server. Leave the other computers alone for a moment.
Have the host start a single-player game. All maps work, with the exception of FuShe Pass. Set the necessary options (such as bot difficulty and map) and start the server.
Once this game has been created, have the other computers click on the old server in the server browser and connect.
There are third-party mods that increase bot count to 32 (and possibly 64 in the near future) and increase the map size, as well.
