The Basic Game:
You move your fist like when you do rock-paper-scissors, and then do a move. However, the moves are different. Moves consists of Charge moves, Attack moves, and Defense moves. You also say the name of the move when doing said move. You win when an attack move "hits" an vulnerable opponent, usually Charging. Same moves usually cancel out each other. If no one wins, repeat until one wins.
Charge: Charge. Say "Charge!". Put your arms in a muscle flexing position. This gives you a charge to be able to Shoot a Fireball. You use up one Charge per Fireball, and use three Charges per Teleport. You may bank on Charges as long you can keep count of them. If both do Fireball, both cancel out.
Shield: Defense. Say "Shield!". Cross your arms in front of you like an X to block a Shot (Fireball). This renders the Shot ineffective. You do not need a Charge to use the Shield. But it is not advisable to Shield infinitely as allowing your opponent to get 3 Charges and Teleport behind you will kill you.
Shot: Attack. You must have a previous unused Charge to use Shot. Say "Shoot!". "Fireball" also works. Put your palms together and extend them out as if making a dragon breathing out a fireball from your hands. A Fireball kills someone who is in Charge. A Fireball is blocked by Shield. A Fireball does not hit someone who has Teleported behind you. This uses up your previous Charge.
Teleport: Attack. If you have 3 or more Charges, you may use Teleport. Say "Teleport!". Put your index and middle finger like a gun and put it on your forehead. Teleport kills opponents in Charge, Shield, and Shot (as it Teleports behind you). If both Teleport, nothing happens as it is canceled out. This uses up 3 Charges.
The Teleport ensures the game will not go on indefinitely unless both opponents do infinite Shields.
Three Lives or Health.
Maximum of 3 (or so) Charges.
Add more House Rules as you wish.
Shieldbreaker: Attack move that uses 2 Charges. Yell "Shieldbreaker"! Kills Shield as well as Charge, but not Teleport. You may do a sword slash move. Two Shieldbreakers cancel out. A Shieldbreaker and Fireball cancel out.
Backstab: Attack move that uses 1 Charge. Defeats only Teleport, but is vulnerable to all other Attack moves, and does not do anything to other Defense and Charge moves. Backstab cancels out Backstab.
Absorb: Defense and Charge move that uses up 3 Charges and absorbs opponent Attack move Charges. A Fireball gives 1 Charge, Teleport 3 Charges, etc. If there are no opponent Attack moves, 3 Charges are drained. (This allows an attack to the next turn).
Super Shield: Like Shield but cancels out Shieldbreaker, and uses up a Charge.
Make up new moves as you wish. Make sure they are balanced.