Go back to the midevil times and fight your freinds the old fashion way except Minecraft style. Get into a mincart and have the king/host press the start button.
If you would like this on your server, message me on my PMC or look for me in game as Willcf.

How to play: Have both players put on their assigned armor and wield their diamond sword. Have both players go to bed than follow the path next to their beds. Than have both of them get into the carts. Wait for host to start the game than when driving by, hit each other only once. Host may change the rule so they can hit each other more times if they like. Who ever dies or falls off first wins.

Host: Wait for both player to enter their minecarts than press the open spectate-area lever. Go across the sand"bags" than press the start game and watch the may-ham begin. If you like you can close off the winners prizes area which includes Enchanting bottles (They are only allowed to take 5 each win) and a enchanting table.
You may change the prizes or weapons if you like.

Reccomended settings: (optional)
Play on Peaceful or Hard.
Use Gold and Chainmail armor.
Hit each-other only once when riding by.

Enjoy!