* A general one for DragonballZ. Satan/Hercule somehow convinces everyone that not only was Cell simply using bombs when he destroys the military on camera but also that all of the real fighters at the Cell Games were simply using tricks. There are two problems with this. The first is that we and the people watching the video clearly saw Cell being hit by missiles multiple times to no effect. Bombs do not grant near-invulnerability. The second is that this is the same world where, only a little over a decade ago, Goku, Kuririn, Tenshinhan and many others were filmed ''live'' in a major tournament using those same 'tricks' with the announcer and the audience clearly aware of what those 'tricks' were. This is the same world where Master Roshi (as Jackie Chun) ''blew up the freaking moon'' and King Piccolo ''took over the planet''. Even if you want to argue that those events all took place in the early manga which was far more lighthearted it still doesn't make any sense because Nappa clearly blew up a camera crew by pointing at it and at the time of Satan's claims Cell has just finished consuming a vast portion of the human population. Has everyone taken collective leave of their senses?
** This isn't helped by the fact that Mr. Satan is, by and large, a CreatorsPet. The level of favoritism and special treatment he is given borders on ridiculous. First we have Cell inexplicably sparing him and his "posse" when they challenge him at the Cell Games, even when Mr. Satan keeps on insisting that Cell is cheating and that it's circumstance, not his own weakness, that is the cause - Cell even internally muses on how utterly painful it is to listen to Mr. Satan and endure his stupidity beyond stupidity, so why did he not kill him when he was both annoying him and calling him a liar? The excuse that he didn't want to expend any ki to kill him is nonsensical after-the-fact HandWaving to keep Mr. Satan alive because the ''DragonBallZ'' mythos confirms that it would require little to no effort to kill Mr. Satan. Then come Buu Saga and Mr. Satan is given an inordinate amount of screen time, Majin Vegeta spares the idiot, Buu spares him, and he is left the last human alive, and even more shockingly, when it comes down to a choice for TheHero, Goku, on which lives to save when Buu is charging up his planet-destroying blast, his sons and Piccolo, all strong, capable fighters who could have given Majin Buu a run for his money, or Mr. Satan and the healer, he chooses Mr. Satan.
** Vegeta and Gohan's respective lapses of logic during the Cell saga certainly make one want to smack oneself given how after the events of the Freeza saga both should know better. Both of them should know firsthand not to underestimate Cell: Vegeta knew just how dangerous a powerful enemy could be and that it was best to finish them as soon as possible, while Gohan knew a foe could pull something really nasty if desperate enough given how Freeza reacted when he was outmatched while fighting Goku. But Vegeta instead helps him get stronger and Gohan later proceeds to spare Cell because he's having too much fun dragging their fight out regardless of the consequences. Krillin's move of sparing #18 can be viewed as this, but it can also be somewhat justified since he may have assumed that Vegeta wasn't holding the IdiotBall at the time and would destroy Cell before he absorbed her rather than helping him succeed in the task instead.
* During Goku's final battle with Piccolo at the end of the original ''Dragon Ball'' series, Kami tries to help him out and Goku (in the Funimation dub, at least) responds by saying "This isn't your fight, Kami," and then [[HonorBeforeReason giving Piccolo a free shot at him to make things "fair"]]. Given that Goku was literally fighting [[LiteralSplitPersonality Kami's evil half]], one would think that this was a hell of a lot more Kami's fight than it was Goku's. Goku was completely out of line, yet the battle ends with Kami not only admitting to his righteousness, but offering Goku his job!
* Goku giving Cell, an active threat to the world at large, a Senzu bean before sending Gohan to fight him. The world IS at stake here. Fuck fair fights!
** Goku's entire "plan" for the fight against Cell. Goku wants Gohan to fight and finish him off, because he knows that Gohan can be stronger than any of them at that point if Gohan becomes angry enough, as was indicated in the earlier arcs when he attacked Raditz and Nappa in a rage. So Goku not only stops fighting Cell and, as mentioned above, ''gives him a Senzu bean to heal him'', but sends Gohan into the fight and just stands there ''while his only son is about to be crushed and die'', having not bothered ''to tell'' Gohan his plan! Fortunately, Piccolo [[CallingTheOldManOut calls him out on this]] and [[WhatTheHellHero chastizes him]] about what a dumb plan that is, not to mention the fact of ''not'' mentioning it to Gohan and even explaining to Goku ''why'' his plan was failing so hard.
* Uub's placement in Dragon Ball GT. After Goku left for ten years to train him, Uub returns in the Baby arc. So what does he do? He gets beaten by Baby, fuses with Buu to become Majin Uub, gets beaten again by Baby and eaten, paralyzes Baby long enough for Goku to kill him, gets beaten by Super Android 17, and finally does nothing while fighting Omega Shenron. Ten years of training, huh?
** And that's not even the worst part. The worst part is how he's the third strongest "hero" character (After the two Super Saiyan 4s), yet everyone treats him like if he was [[OvershadowedByAwesome Yamcha]].
** To put it in even clearer perspective, Uub has the power of a monster that almost no single character could beat on their own, plus several years of martial arts training from Goku and a power-up from Fat Buu that should make him at least as strong as Super Buu, yet he has no real impact on any major battle. Why was Kaioshin scared of him again?
* Here's one in the Buu Saga...Gotenks and Vegeto are enjoyable, but one can't help but wonder why these two would fool around when battling Buu when the Earth was at stake and Super Buu killed/absorbed their friends and family!
** Unfortunately, Fusion seems to bring out the worst traits of the combined characters it seems like. Granted, Vegito wanted Buu to absorb him so he could free the others but Gotenks could've defeated Majin Buu when he was Fat Buu but he would rather show off and make an idiot out of himself that he got creamed. Bad enough in the rematch against Super Buu instead of going into Super Saiyan 3 immediately he decides to waste time and perform numerous moves that have zero effect on him and it takes Piccolo nearly about to strangle him to get him to fight seriously but by then his fusion time is up. If he had done so, [[CouldHaveAvoidedThisPlot Buu would've been destroyed and not escape the Time Chamber and eat the rest of the Z Fighters.]]
** They Both just got screwed by plot. Gotenks got screwed by Buu's ridiculous level of regeneration, Vegito got screwed twice by first being dissolved and then Buu becoming stronger after saving everyone.
* The fact that Android 19 can ''feel fear''. Didn't it ever occur to Dr Gero to leave that out of his programming? As far as he knew at the time, 19 was far stronger than any of the Z Fighters, let alone any other creature on Earth, so why would he allow him to have an emotion that could only be a liability in combat?
* When thinking of wall-banging moments, the perennial scarcity of [[HealingPotion Senzu beans]] springs to mind. To contrast, in Dragon Ball, Goku chomped down a whole mouthful of them, ignorant of the fact that one Senzu bean is enough to keep a person full for ten days. But come Dragon Ball Z there's never more than a meagre handful of the bloody things available at any time. I don't know the secret art of cultivating Senzu beans, but the constant lack of them is starting to border on DramaPreservingHandicap by the time the later sagas roll around the corner. How many beans are left for Goku to pick up during the early Buu saga? ''[[RuleOfThree Three!]]''