Black Ops 2
Online Custom Games: Unlimited Lives On Search And Destroy
Tutorial
Step 1. Get a custom game type of SnD from one of the legit hosts on this site.

Step 1. Join one of there lobbies(The game does not need to be started, all your trying to achieve is getting them on your recent players)
Step 2. At the main menu pull up your recent players by pressing "Y" then find the hosts gamertag under the recent players tab at the top.
Step 3. Click on there gamertag, then choose player channel.
Step 4. Go to the custom games tab, and save there SnD game type.

Step 2. A continuation of the first step, not the italicized steps)Go to custom games and load the custom game type you just saved. And pick that map that you are wanting to host on.
(Note if your custom game is not showing up dashboard and load your Call Of Duty game back up and it should be there)

Step 3. Back out of the custom game lobby. You should now be at the public match, league play, etc. etc.

Step 4. Search for a game of Core SnD and once it starts searching back out immediately, you don't want to be put into a game.

Step 5. After you have backed out click on your gamertag and then click on player channel and find the custom games tab. You need to click once on your custom game type of SnD, it will ask you if you want to load it. Now hover over "Yes" and click "A" and "B" at the same time. If done right it will put you into a custom game lobby.

Step 6. Back out of the Custom game lobby, do not edit anything.
You should now be back at the public match, league play, custom games, etc. etc.

Step 7. Hover over custom games, now comes the hard pert. You must press "Y" and find a friend that's at the main menu and is joinable. Press "X" to join his session, while it's joining you need to spam "A". You need to stop spamming as soon as the join in session pop up goes away. If done right you should be at the public match, league play, custom games etc. etc. menu, and it should show a score of zero next to your name and you will be in a games by yourself. If anything else happened you did it wrong.

Step 8. Repeat step seven one more time, the same thing should happen but your team color should change if done right, everything else should also be the same.
(Score zero, orange color behind your gamertag, etc. etc.)

Step 9. Invite seventeen people and fill the lobby, once it's full click your name in game and go to your player channel. Go to the custom games tab, then select your SnD game type. After you select it nothing should happen, it should only close the pop up on your screen that you opened when you pressed "Y".

Step 10. Start the match by clicking public match, if anybody lagged out try to invite them back before the game starts or they will not be able to get in.
Step 11. Enjoy boosting in SnD with unlimited lives, if the game ends and your stats don't stick it's because you went over the XP limit.
On a side note, this works with any game type and allows you to bring custom settings online.