Other kids' games are all such a bore!
They've gotta have rules and they gotta keep score!
Calvinball is better by far!
It's never the same! It's always bizarre!
You don't need a team or a referee!
You know that it's great, 'cause it's named after me!
You wanna...

-- Calvin

Ball game invented by Calvin and Hobbes. Rules include:

  1. All players are required to wear a Calvinball mask. This regulation is not to be questioned.
  2. All following rules may be changed, amended or deleted by any player involved at any point in the game.
  3. Any player may declare a new rule whenever he/she wants. This can be done audibly or silently, depending on the zone the player is in.
  4. The Calvinball may be used in any way the player sees fit, whether to cause injury to other players or to gain benefits for himself.
  5. Any penalty legislation may be in the form of pain, embarassment, or any degradation the rulee wishes to execute upon the other player.
  6. The Calvinball field consists of areas, or zones, which are governed by a set of rules declared by players. Zones may be appear and disappear as often and wherever the player decides. For example, a corollary zone would enable a player to make a corollary (sub-rule) to any rule already made. Or a pernicious poem place would require the intruder to do what the name implies. Or an opposite zone would enable a player to declare reverse playability on the others. (Remember, the player would declare this zone oppositely by not declaring it.)
  7. Players may name flags, assigning their powers and the rules governing the use of the respective flag.
  8. Songs are an integral part of Calvinball and verses must be sung spontaneously through the game when randomly assigned events occur.
  9. Score may be kept or disregarded. In the event that score is kept, it shall have no bearing on the game nor shall it have any logical consistency to it. (Legal scores include 'Q to 12', 'BW-109 to YU-34, and 'Nosebleed to Pelvic Fracture'.)
  10. Any rule above that is carried out during the course of the game may never be used again in the event that it causes the same result as a previous game. Calvinball games may never be played the same way twice.
  11. A Calvinball may be a football, volleyball, or any other reasonable ball.
  12. The Calvinball field should be any well-sized field, preferably with trees, rocks, grass, creeks, and other natural obstacles.
  13. Other optional equipment includes flags, wickets (especially of the time-fracture variety), and anything else the players wish to include.

Source: Comprehensive Calvin and Hobbes (http://www.geocities.com/SoHo/Nook/2990/index.htm). However, this is *not* a cut-and-paste job.