The Forge and the Theater are two of the best additions to the Halo series in Halo 3. Both of which are accesible in the main menu, or you can switch to the "lobby" of your choice from any other lobby.

Basically, the forge is an object editor in multiplayer maps and the theater is a place where you can watch previous campaign levels or multiplayer matches.

Forge

In forge, you can delete most objects and place map-appropriate objects. (By map-appropriate, I mean that not all maps feature every single item, weapon etc...there are limitations.) You are also able to place spawn points for any team, edit the placement of goals (flags, etc).

You are able to save any edited maps and load them later, share them with friends and even play custom games with your friends over Xbox Live or System Link.

The forge and custom game lobbies (two seperate lobbies) work together. Forge designs the map while the custom game variant designs the rules. All you have to do to make the perfect gametype is to make and save your custom game of choice, and make and save your map variant of choice. Confusing? Bah...you'll get used to it very quickly.

There is a maximum amount of each item you can place on a map, and there is also a budget for each map. If you place X amount of objects on a map and the budget reaches to where you only have $10 left, you can only place one or more objects that does not surpass $10. Deleting previously set objects will lower your budget as well.

Despite the few limitations, forge is my personal favorite addition and great fun when you get used to it.

Theater

The theater is a place, (as stated above) where you are able to load up any previous multiplayer match or campaign level played. All you simply do is go to the theater lobby, select your film and load it up. Twenty five of your most recent flims will be automatically saved, however, you are also able to save films and put them into your theater library.

There are limitations while watching a film of campaign that do not apply to multiplayer. While watching a film of multiplayer, you are able to rewind and record clips. This is not available in campaign.

In both campaign and multiplayer, you are allowed to fast forward, pause, activate slo-motion, take screen shots and free roam the camera to get the best angle for that best screen shot.

If connected to Xbox Live and if you have an account at www.bungie.net with that account connected to your Xbox Live gamertag, screen shots will automatically be saved to your profile at bungie.net.

Please note that saved films is nothing more than a saved recording of the game data, therefore it can only be played back inside the game, and nowhere else (such as your computer).