Long ago, there were two armies that constantly fought against one another. One fought for purifying light and justice, the other for concealing darkness and unity. These two armies would not stop their slaughter against one another, until a creature that was neither light nor darkness banished these armies into two dimensions, Hyperspace and Subspace. The creature then disappeared from legends for all eternity, leaving behind only his R.O.B.s to protect them from both armies, just in case they left their dimensions.

Many years after this, heroes and villains of all shapes and colors transended onto the once battlefield of these armies, in hopes of good fortune and other things. However, they would not actually die when beaten, but rather transformed into trophies. All was in balance, until one villain took measures too far. This villain through his many years of sorcery and dark magic opened a portal that led him into a world of Darkness and destruction. This wizard was corrupted by its power and decided to tap into it. However, he became nothing but pure darkness, able to create more darkness of his own. However, before he could show his extraordinary powers, he was captured by the leader of Darkness, called Tabuu. Tabuu saw this wizard as his key to winning a war that no one had seen for millenia, he used the wizard's capabilities to clone his armies with greater and greater power. Soon, the villains of the "Neutral Dimension" came across this portal. Tabuu did not want an audience quite yet, so instead he used his powers to control a disembodied hand to command the villains to do his bidding.

The heroes soon got involved and eventually came through a separate portal into Subspace. Here they faced against the creature of pure darkness, Tabuu, and were victorious. However, they did not count on two things, the first was upon defeating Tabuu, they had triggered the second army to awaken, and the second was that Tabuu was not dead. He sensed his enemies coming through their own portal, and decided to let the war happen once again, this time the "Neutral Dimension" people shall be the armies.

The leader of the Light army, Aalow, was also for this 'little game'. He too would make peace with anyone that he could and anyone that would dare to fight them, would be exterminated. Aalow started by making peace amongst the heroes to become their allies, revealing that Light is good. Tabuu on the other hand did not like this one bit and decided that he himself shall recruit people (and animals depending) by revealing the Aalow's true intentions. However, not a lot of the heroes or villains were convinced, but he took what he could to help fight the war. One last (Technical) army was created because of this revelation though. An army that decided that both the armies of Light and of Darkness are both the villains. An army known solely as the rebels. However, this war is bigger than the fight in Super Smash Bros: Brawl. This war is.......Super Smash Bros. Alliance!