One of the emotional high points of the anime series Dragon Ball Z involved Goku passing the torch to his young son Gohan as Earth's defender during a kinetically charged showdown against Cell. Taking place at a martial arts tournament thrown by the villain, aptly dubbed the "Cell Games," Goku battled against Cell before opting to have Gohan take his place and reveal his true power to destroy the evil android once and for all.
And while this plan ultimately worked out in the end -- albeit at the cost of Goku's life -- this bold strategy almost ran completely off the rails until Gohan realized what his father was up to and revealed it to Cell himself.
While training with Gohan in the Hyperbolic Time Chamber, Goku noticed his son had achieved the potential to transform into Super Saiyan 2 if properly pushed. After exiting the Chamber, Goku quickly realized Cell was actually stronger than he was, but remain unfazed as he quietly developed his strategy to have Gohan become the Earth's next savior. Every time Gohan previously tapped into his anger, the fury would elevate his combat strength significantly, so Goku reasoned he could place Gohan in a position for this to become possible at the Cell Games. He set his plan into motion by surrendering after his own skirmish with Cell, shocking the rest of the Z Fighters as he volunteered Gohan to take his place.
The big issue with Goku's plan is that it assumed Gohan, unaware of what his father was up to, would be pushed to a point in combat where he would lash out and trigger his full Super Saiyan 2 transformation. As Gohan stepped up to fight, however, he understood the position his father had put him in. The young Saiyan refused to fight back against Cell, unwilling to get angry precisely because of the uncontrollably violent potential he was capable of. As Cell grew more frustrated, he created a squad of Cell Juniors to attack the rest of the Z Fighters to further goad Gohan into fighting, with the last straw snapping when Cell destroyed Android 16, sending Gohan into a rage.
However, Cell only escalates his efforts to make Gohan fight after the young warrior reveals to the villain exactly why he's holding back -- even with Earth's fate hanging in the balance. Cell could have just as easily grown bored or frustrated and simply killed Gohan on the spot. However, Goku bet the fate of humanity that Cell was just as arrogant as Vegeta had been in allowing him to reach his perfect form. While things appeared grim for a bit, this bet would ultimately pay off.
Dragon Ball is a franchise full of cocky characters who often tempt their own luck by allowing opponents to grow even stronger. This theme is prevalent in the various anime and manga series and has been the downfall of many powerful antagonists. The Cell Games perhaps exemplifies this theme most explicitly, but it also ran dangerously close to unraveling had Goku's intuition -- about his own son as well as Cell's arrogance -- been proved wrong. Goku's grand plan to save the world and pave Gohan's destiny succeeded, but hinged on Cell learning about the plot himself rather than Gohan willingly ascending.
