The objective is to locate the Skull(s) on the map and to maintain possession of it for the longest period of time possible. The default settings allow the game to be a free for all with one Skull on the map, which you need to have possession of for two minutes in order to win. This game can be played as a Free-For-All Game or a Team Game where the highest score of the lone player (FFA), or on a team's accumulative score, chooses the victor(s). Normally, a player who has the Oddball is the immediate target for the other players, which is what makes Oddball an extremely fast paced and fun game-type.
While a player has possession of the Oddball, they cannot wield their weapons or throw grenades. However, they can still melee opponents with the Skull, which normally inflicts massive damage. The settings for the game can also be altered to make it more interesting. For example, the player with the Oddball can go invisible or can be slowed down. The number of Oddballs on the map can also be changed. Oddball in Halo 3 is the same and looks just like the Skulls of Halo 2.
- Get ready for a classic game of free for-all Oddball. Hold the ball for 2 minutes to win.
- This game of Oddball, with nothing but Rocket launchers, is a real blast. Control the ball for a total of 1 minute to win.
- Tense rounds with swords and no motion sensor. Control the ball for 30 seconds to win a round. First to 3 wins, a very deadly game.
- Main article: Team Ball
- Up to 8 teams can go head to head in this game of team oddball. First team with 2 minutes ball control wins.
- Team Oddball with a twist. Everyone on your team must hold the ball for at least 30 seconds to win.
- An odd game of ball with random weapons. Earn 2 minutes control time to win.
- Main article: Ninjaball
- A Halo 3 variant that grants the Oddball Carrier with more speed and less gravity, but cannot take as much damage.
- Oddball, is derived from Marathon's "Kill the Man With the Ball".
- In Halo 3 multiplayer, if you melee an enemy with the Oddball it is an instant kill, however, this can be tweaked via the game setting in all of the Halo games.
- Getting three Oddball kills on a Legendary Map unlocks the Alas, Poor Yorick achievement.
- In Halo 3, if you go to the game settings in the Custom Games lobby, go to Oddball Settings and change the ball number to two, a little notice appears at the bottom saying, "Players fight over two objectives. Ha, thought I'd make a ball joke, didn't you?"
- In Halo: Reach, the Oddball is on fire, much like the Headhunter skulls.
- On the base of the Oddball is a Neural Interface implant seen in Halo: Combat Evolved.
- In Halo: Combat Evolved, in the oddball section, if you go to the edit section to change the number of balls, a joke will appear in the bottom of the screen, depending on the number of balls.
- In Halo 4, assassinations are possible with the skull which vaporize the target like Forerunner weaponry, as well as the ability to wield a pistol with a flag. These were first shown at SDCC 2012.
- In Halo 4, the Oddball is a spherical container containing a light blue holographic skull. The "ball" part consists of black metal brackets that surround the skull. The brackets are positioned to emerge from the back of the skull and leave the 'face" area open. It also serves as the Grifball.
- In Halo 4, the ability to throw the Oddball was added. It has resulted in the gametype being much faster paced.
- In Halo 4, the skull seems Forerunner rather than Human, as it is blue, holographic, has a faintly visible Promethean Knight-like skull in the center, and disintegrates with Assassinations.
- In Halo: CE, Juggernaut is an Oddball game type.