Murderball began as a version of Four Square with standard rules, including that the player in the 4th square is able to modify the rules.
Base Rules:
- The standard murderball court is a 3x3 square, snaking from Square 1 to 9.
- There is one player per square, all other players form a line behind square 1.
- New players enter at square 1.
- Square 9 is King/Queen and can make any rules they desire.
- Players are murdered if a ball strikes them anywhere but the hands/wrists.
- Murdered players go to the back of the line, play does not stop.
- If the ball touches a square, then bounces out, the player in the last square it touched is out and play stops.
- Players who are waiting to play (Those not currently in one of the 9 squares) are considered "Interference" and may attempt to hinder or help those inside the squares. They may not enter any of the squares in their attempts.
Courts:
| 4 | 3 |
| 2 | 1 |
| 9 | 8 | 7 |
| 4 | 5 | 6 |
| 3 | 2 | 1 |
| 9 | 8 | 7 |
| 4 | 5 | 6 |
| 3 | 2 | 1 |
Standard square court. Open walls, 2x2, 3x3, 4x4 squares. Best for: parking lots, driveways.
| 6 | 5 |
| 4 | 3 |
| 2 | 1 |
Murderbay. Walls on 3 sides, playing off walls is allowed, and walls are not considered part of a square. Best for: truck bays, loading docks, squash courts, alleys.
Modifiers:
- Aerospace: If there are walls adjacent to any squares, those walls are considered part of the square, and balls bouncing off those walls can get those players out as if the ball hit the square (if it goes out afterwards).
- No Spiking: You cannot bounce a ball over another player’s head.
- Catching: If you catch a ball before it bounces, the last person to hit the ball is out.
- NBA Jam: After murdering 3 other players within one life, the murderer is considered “On Fire”
- "On Fire" players cannot be murdered. They can only get out by having the ball bounce out of bounds from their square, or off their body.
- Solar Power: Players standing in the sun are "On Fire"
- Pokemon: After hitting the ball, name a pokemon. If a player fails to do so, or if a pokemon is repeated, that player is out.
- Pirate: All players close one eye of their choice.
- Ice Climber: The King may name a player who will join another player in their square, and help them out. Ice Climbers are murdered individually but the square gets out together.
- Pac Man: The King may choose one player to run along the lines of the court during play.
- Soccer: You may now only touch the ball with your feet/legs/head.
- Dinosaur Arms: Players must keep their elbows locked at their sides, decreasing their reach.
- Back Hand: Players may only use the back of their hand on the ball.
- Tennis: When hitting the ball, you must grunt as though you were a Tennis player
- Bumpers: Interference are now only able to help people inside the squares by keeping the ball in play
- King's/Queen's Guard: Players that are declared as a King's/Queen's Guard must help the King/Queen survive. If the King/Queen is gotten out or murdered, all members of the King's/Queen's guard are also murdered as a subsequent action, meaning they get in line after the King/Queen
- Jaeger: Two players enter a square together. They must attempt to synchronize their movements to the best of their abilities. While they are in sync, they are considered "On Fire"
- Volleyball: The ball must be hit up in the air and if it lands in a square, that square is out.
- Extra Head Hit: You can hit the ball one extra time, but only with your head (before or after a normal hit).
- Extra Life: If you somehow get an Extra Life, when you would be out, you can call EXTRA LIFE and stay in your square. This applies to both murder and otherwise getting out. (Then you don’t have the Extra Life any more.)
- Master Vampire: One player is designated Master Vampire. Everyone else is human. When Vampires murder, they gain an Extra Life. Anyone killed by a Vampire becomes a vampire as well (able to gain extra lives by killing humans).
- Optional: You stop being a Vampire when murdered (by anyone).
- Vampire Hunter: When you murder a Vampire you gain an extra life. Non-masters killed this way stop being Vampires.
- Optional: Any human can become a Vampire Hunter by murdering a Vampire (they don’t get an extra life the 1st time, but after they they are Hunters).
- Multiball: Throw multiple balls at once. Any of them can murder someone. You only get out for the ball hitting your square and leaving play if it was the LAST active ball.
- Bonus Ball: Designate someone to get a Bonus Ball (often something like, “Square one” or “Last person out”). That player gets a ball before the main ball is served. They can throw it whenever they want, starting “multiball”, but if the bonus ball goes out of bounds it can’t come back in.
- Wacky Ball: Players must use a ball with an obvious deformity, typically in the form of a bulge, which causes it to bounce in an erratic and unpredictable manner.