I Am Not Left-Handed/Playing With

Basic Trope: A character reveals a hidden level of power late in a climactic battle.
 * Straight: During her showdown with Emperor Evulz, Alice is getting beat fairly badly. She then reveals that she was only using about 85% of her power, and powers up accordingly, eventually winning the battle.
 * Exaggerated: Alice was only using 1% of her full power.
 * Justified: Alice didn't know the scope of Emperor Evulz' power, and wanted to keep some of her power in reserve to make sure that she didn't use it all up before she could finish him.
 * Alice's true power could cause a great deal of destruction, but Emperor Evulz has pushed her over the Godzilla Threshold so she can't afford to hold back.
 * Inverted: Alice discovers a crucial weakness during her battle.
 * Subverted: Alice was lying...the power increase was for show.
 * Double Subverted: Alice says she's powered up to 100%, so Emperor Evulz does the same. While the Emperor fights much better, Alice doesn't get any stronger. In truth, she was just making sure the Emperor was showing his final form before she powers up for real, knowing he is out of tricks.
 * Parodied: Alice has a power increase for every roadblock Emperor Evulz throws her way.
 * Deconstructed: Alice's power increase comes too late - it's not enough to win the day, and she goes down fighting.
 * Reconstructed: Alice did enough damage with her power increase to deal a serious blow, despite the lateness, and both sides live to fight another day.
 * Zig Zagged: Alice says she's powered up to 100%, so Emperor Evulz does the same. While the Emperor fights much better, Alice doesn't get any stronger. In truth, she was just making sure the Emperor was showing his final form before she powers up for real, knowing he is out of tricks -- but it still isn't enough, and Emperor Evulz wins.
 * Averted: Alice fights at full power the whole time.
 * Enforced: "Look, we've got to please both Alice's and the Emperor's fanbases, so let's have him beat her silly until she reveals she's not using her full power!"
 * Lampshaded: "I'm not done yet! What I've been telling you is 100% power is really more like 85%!"
 * Invoked: Alice decides early on she should never go into battle 100% so she'll always have a trump card.
 * Defied: Emperor Evulz forces Alice to power up fully at the beginning of the battle.
 * Discussed: "Let me guess...you're holding back some of your power."
 * Conversed: "She's not using her full power? What a copout!"
 * Played For Laughs: The whole thing is a Lensman Arms Race in power increases - the fight goes on for hours with each side increasing their power sporadically.

I know you thought I was finished with this trope entry, but I Am Not Left Handed!