You can play different games on different mapes.
Here are what games you can play on the maps.
Legend
X Game is available.
+ Game can be played using the Dark vs. Light trick (see below)
- Game is unplayable.
The game can be started as below, but there will be no Bacon or Last Man flag.
Capture the flag and Balls on Parade games will result in the immediate termination of all teams, since they have no flag or ball.

Map	Body Count	Steal the Bacon	Last Man on the Hill	Scavenger Hunt	Flag Rally	Capture the flag	Balls on parade	Territories	Captures
Desert between your ears	X	-	-	-	-	X	+	X	X
If I had a Trow	X	-	-	-	-	X	+	X	X
Mudpit massacre	X	X	X	X	X	-	-	X	X
MM (Dark)	X	X	X	X	X	-	-	X	X
Ground Zero	X	X	X	-	X	X	-	X	X
GZ (Dark)	X	X	X	-	X	X	-	X	X
I'll dance on your grave	X	X	X	X	X	+	+	X	X
I'll dance on your spiderweb	X	X	X	X	X	+	+	X	X
For carnage apply	X	X	X	-	X	-	-	X	-
Carnage (Dark)	X	X	X	-	X	-	-	X	-
Creep on the Borderlands	X	X	X	X	X	X	X	X	X
Rest in pieces	X	X	X	X	X	-	-	X	X
RiP (Dark)	X	X	X	X	X	-	-	X	X
Death in dire marsh	X	X	X	X	X	-	-	X	X

How to play games marked +.
(Ok, this is just the famous Dark vs. Light "bug")

Select Creep on the borderlands, because it has all the games. Set up everything as you want it except the map.
You will need to distract Myth by some keyboard action while clicking on the map you want.
I prefer naming the game to something long and move the cursor from one end to the other.
Other sites recommend pressing space till the name box is full and then press backspaces.
Either way it's the same thing, you fool Myth to process the keyboard presses while you manage to click on the map you want. Keep distracting Myth with clicks after your click.
The trick is to get the right interval between the keyclicks. To much time between keypresses and the map and game will change and you will have to set it up again. To short time and your map click will be ignored.
The interval depends on your computer, it will take some practice.
Once you get it right, click OK and leave the option screen.

You can play solitaire games on Bungie.net by logging on and starting a single player game.
However if you have a Mac you can start a solitaire game. You can probably do the same on a PC with TCP/IP, but I dont know. On my Mac selecting TCP/IP will start up my modem.
This works for me, should work for you. You need AppleTalk installed, but it does not have to be activated.
Select Multiplayer Game, then Other in the upper right corner. Select AppleTalk and press OK, then on the next screen press Create. That should be it. You can now play the game you want. You might get an error here, in that case try pressing Create again a few times.

You can play a game on a map against "drones", that is inactive computer players. Select the map you want, use the distracting trick to click on "use solo maps". Start the game. This will not be any type of game at all. In fact you cannot win nor loose this game, not even with Ctrl-Plus. There will be no planning nor trading. There will be no time limit, but the clock will tick. It seems you always get two (or less) computer opponents and the three (or two) of you always start in the same positions on the maps. The computer players will just stand still till you get within their reaction range.
This game is pretty useless, except it will allow you to practice ghôl pus-packets or dwarven-fetch battery tactics against enemies.
One thing you could to is set up a short mental time limit, and try to eliminate the enemies within that limit.

Capture the Flag

Each team has a flag. The winner is the player who at the end of the game controls the most flags. If at any time a team does not control any flag, that team is eliminated.

Notes:
You only need to hold a flag to stay alive, not neccessarily the flag you started with. So being aggressive can pay off. I have knocked out 2 other players with small losses in such games.

I discovered this game about 3 weeks ago. Thanks to Electrofryer. Played with the right people this game can be really fun.

This is a secret for those who bothered to read this far. It can only be used on LAN or over IP. Check it out.