Rp is short for role play, this is where you type out your characters actions and someone replies or you do it by yourself, this is much more fun way to battle than to just have the normal hp and stats way. this way can be much much more creative.
Rp may be rewarded, you will be informed if it is.

Good rp doesnt say you automatically hit them e.g You throw a punch and knock a fighter cold. Thats bad and shouldnt be done if your just starting out. A better way would of been: You throw a hard punch towards a fighter, then the fighter replies.
You can practice your rp on the rp practice board and heres a rather small example of a fight:
Finished powering up the pair stare at each other before gremlin dashing in his opponents direction and disappearing about half way, the saiyan turns around to see the icer reappear behind him and the icer launches a punch with one hand and gets a small guided ball ready in the other. Knows that this is gonna hurt, the saiyan decides to play it defensivly, and uses energy shield to defend the guided ball that will be launched at him in minute. A flicker catches the icers eye as a defensive orb flawlessly appears around the saiyan just before his punch connects, it slams into the energy shield rippling and the guided ball follows straight into it creating a whole but it is quickly refilled. Gremlin growls and dashes back about 30 meters before a faint aura appears around him and 30 balls of energy go flying at the the side facing hte icer of hte shield is holy but doesnt falter and the icer prepares to make a guided blast, charging it slightly bigger than normal then launches it straight towards the shield creating a massive hole, forcing the shield to flicker as it attempts to find the energy to refil the hole. The energy shield wears off from the blasts made by the icer, the saiyan figures out a way that could beat the icer, but this will take some time, first things first, the saiyan blasts off into the sky using Adv Flight. The icer isnt about to let his pray go away and gremlin dashes after him, his adv flight isnt quite catching up so he decides to phase infront of the saiyan stopping him dead in his tracks awaiting the next move. instinct knew that the icer would appear infront of him quickly using guided blast that rips right infront of the icer, the blast caused the saiyan to loose abit of ki, but still has enough energy for the counter-attack. The Icer blocks and the ki pushes him back about 5 meters but it is then sent straight back at his opponent and he drops his altitude slightly to about 2 meters above the ground.The Saiyan quickly dodges the attack, but the blast slightly got him on the right arm, its all burnt and bloody, the saiyan looses altitude as the same level as the icer, the saiyan yells from the top of his lungs releasing unbelivable power, an aura surrounds the saiyan with full strength. He then uses guided Beam stright at the icer.The icer goes flying backwards as the beam explodes on him sending him into a few trees then a huge pile of dust is kicked up as he hits the ground. the saiyan quickly takes this time and attempts to fire as many guided balls as he can at the place where the icer fell. one two three balls hit him at once followed by a few more. the saiyan thinking the fight is over falls down the the ground waiting for his energy to return