You are a powerful wizard who is battling another powerful wizard. (You are on the right). You and your oponant take turns attacking or healing. You get the first turn. On your turn push the a key to attack and the h key to heal yourself. But be warned, Even the most powerful wizards sometimes mess up their spells, so sometimes when you attack or heal, the spell will fail and it will be the next persons turn. When you take the attack action you might shoot a bolt of fire dealing damage equal to your power. When you heal you might create green magic and heal health equal to your healing, (your health can be higher than your starting health, so use it wisely. If you die, by having 0 health left) a screen will pop up and click the play again button to play again. If you win by bringing your opponents health down to 0, a screen will pop up. Push the h key to increase your health by 1, p to increase your healing by one, an L to increase your health by one. Then click the play agin button to play again with your new stats.
If you attack or heal and then one second later something pops up and says, "oh no! It failed" that is the CPU failing and it would then be your turn. If you have a spree of hits or misses, it has nothing to do with the coding it's just luck. Thanks to @MyRedNeptune for the fire sprite animation, everything else is me. @fsh09