Conflict, of all types, is chaotic. There are many forces and interests that can come into play, any of which may be entirely incomprehensible or unforeseen, and any action may ultimately prove beneficial or harmful to the one who takes it.
This is not what the audience wants. People instinctively expect the world to be a sensible and just place, and we expect it to be portrayed as such in fiction. From this expectation comes the idea that Right Makes Might, and the deserving are always victorious. But that's not dramatic, either. A hero whose virtue makes him invincible quickly becomes boring, and an ineffectual villain likewise. Moreover, conflict depicted in this way is not realistic, and rings false to the viewer.
One trope that lies in the middle ground between the idealistic view and the realistic one is the Advantage Ball.
This is a status that is bestowed to one side at a time in conflict. Whoever holds the Ball is not necessarily invincible, but certainly more effective, more skilled than usual, less likely to fall prey to bad luck or Diabolus Ex Machina. Similarly, their adversary is confused, fallible, less accurate in their attacks, more likely to make mistakes.
Ownership of the Ball is determined primarily by morale. Whichever side is more confident has the advantage. This tends to result in Hollywood Tactics: using your resources strategically is not as important as making a show. If you can break the spirit of your enemy, you are probably going to win even if they greatly outnumber you and have a far superior position. On an individual scale, if a combatant is unsure either of his chances, or his reasons, he will fare badly. But once he has an epiphany, is reminded of what he's fighting for, receives words of support from his allies, wins the respect of a neutral observer, or gets news that help is on the way, he will instantly become much stronger, even to the point of forgetting previous injuries. A well-placed World of Cardboard Speech or "The Reason You Suck" Speech can render his enemy demoralised and weakened. In mediums dealing with sound, a Theme Music Power-Up is almost required for these occasions.
Visually, this trope often expresses itself in a Pendulum War, with the side in possession of the ball advancing and the other clearly retreating. Once conditions change, the Ball may bounce elsewhere and those who were advancing suddenly find themselves falling back. It's noteworthy that it happens at both large and small scales, with whole armies or just two combatants.
When one side holds the Advantage Ball throughout an entire fight, it's a Curb Stomp Battle.
- Most fights that isn't a straight up Curb Stomp Battle in later episodes of Dragon Ball Z are a match of 'who has the most transformations'. Every time a character turns into a new form, they hold the Advantage Ball untill their opponent does likewise.
- In this case, being changed into a piece of candy counts as turning into a new form... at least if you're Vegito.
- This follows naturally in Tengen Toppa Gurren Lagann, where, thanks to Spiral Energy, confidence is combat ability. Except for wild cards like the Mugann, the Ball is in the court of whoever is delivering a Badass Boast at the moment.
- Bleach plays with this a lot. In most fights, the ball even gets tossed between combatants at times. Very often strategic use of the Advantage Ball (by the author) results in wins or losses the fandom did not expect.
- Naruto has a bunch of advantages when he has to fight Pain, including a bunch of strong toads to fight alongside him, a new Super Mode, the Ninetails, information on Pain's abilities, and Pain's temporary loss of his Gravity Master powers.
- His earlier fight against Sasuke followed the Dragon Ball Z approach of passing the Advantage Ball for a few rounds by unlocking increasingly more power.
- Batman almost always holds the Ball in direct conflict. Three guys with knives or a dozen Mooks with machine guns, it makes no difference. Therefore, the general method of his rogue's gallery to deal with him is to attack him indirectly, especially by undermining what he believes in and threatening those he values.
- One notable exception is in The Dark Knight Returns. Batman does not hold the advantage in his first fight with the much younger and stronger leader of the Mutants, and is almost killed before Carrie rescues him. Batman learns his lesson and the next time they fight, he chooses the battleground and pulls out every dirty trick in the book to beat him. This time the Ball is firmly in Batman's court and he wins decisively.
- The Ball is carefully minded throughout A Knight's Tale. At the beginning, William and Adhemar are evenly matched, and the latter wins by his greater experience. In the final, decisive joust, Adhemar holds the Ball at first due both to the efforts of his herald and copious amounts of cheating, but after Geoffrey Chaucer gives an impassioned speech, the audience changes sides and William wins without even his armour.
- This is well demonstrated by the Flynning in The Princess Bride, where the advantage is determined solely by who most recently switched hands.
- The film of The Lord of the Rings. In addition to many other lapses in tactical realism, advantage in battle seems to be principally a matter of who makes the most badass entrance, regardless of such matters as numbers and equipment.
- Throughout The Matrix, agents are pretty much unstoppable, due both to their superior programming and the terror the other side has for them. But after Neo's awakening as The One, he can dispatch them with ease (and his team can at least hold their ground). An entirely justified in-universe example.
- In the Star Wars Expanded Universe there's Jedi Battle Meditation: an in-universe Advantage Ball. The side supported by the meditating Jedi is filled with confidence and clarity, while the opposing side is assaulted with despair. Grand Admiral Thrawn once quantified this; apparently, supported by battle meditation, his fighters performed up to 40% better in every category of pilot performance.
- The Church Knights of the Elenium and Tamuli, being basically Paladins, have superlative training and political support. Moreover, they have a fierce (deserved) reputation, and armour which not only protects them, but is also intimidating at the same time. Combining this with the extra plot protection that the named protagonists enjoy, the Knights have the ability to steamroll over practically any force, almost regardless of the opposition's numbers, tactics or equipment. This is taken Up to Eleven at the climax of the Elenium, when Sparhawk is driven into an Unstoppable Rage and kills probably dozens of enemy combatants without effort or personal damage. Soon after, however, he faces The Dragon, a man with considerable anthropic weight, and barely defeats him in single combat.
- This actually comes up in Dynasty Warriors and, to a lesser extent, Samurai Warriors. When you accomplish specific tasks, your side gains morale, which basically buys you more time and progress to defeat the enemy general, by adding or removing soldier units from the battlefield. Especially in Dynasty Warriors, even if you're being completely creamed, if you get over 1000 soldier kills, you get unlimited morale. Then you have hundreds of troops rush in and push back the enemy, for no particular reason than that you're now so cool.
- Most stretches of dialogue in Girl Genius can be described according to this, with the butt of the jokes being the ones not currently possessing the humorous Advantage Ball.
Tarvek grabs the ball! Gil struggles, but Tarvek gets in a solid jab! But who's that? Bangladesh Dupree tackles Tarvek from out of nowhere, grabs the Ball and starts piling on the humiliation... But then Vole appears, charming Bang's pants off with a bloodthirsty Villainous Rant, and picks up the ball. Ball occupied, Gil and Tarvek are able to have a conversation on equal terms, until Othar Trygvassen, GENTLEMAN ADVENTURER!, gets the drop on Vole! But what's this?! Gil goes for the dropped ball, grabs it with both hands, runs with it AND HE SCORES, dropping three of his opponents down a trapdoor to a long fall, and wounds the last - Bang - with a vicious playground taunt! What a game, ladies and gentlemen, what a game!