Straight: Our hero Albert and his companions find the Dragon Breaker Blade, a legendary sword said to be capable of slaying the draconic beasts controlled by Emperor Evulz. However, finding the sword and bringing it out into the open gives Emperor Evulz a chance to steal the blade, meaning that one of the biggest threats to his power is now safely under his control.
Exaggerated: Removing the sword made the ruins they were hidden inside collapse; the displaced monsters attacked the nearby villages and now roam the countryside slaughtering innocents. Meanwhile, Emperor Evulz has his forces seize the sword and uses his dark magics to twist the blade so that it now enhances his powers. Whoops.
Downplayed: Removing the sword releases some chaotic spirits that begin to wreak minor havoc in a nearby village. This results in an optional sidequest to destroy the spirits you accidentally released.
Justified: The Dragon Breaker Blade is, as far as Albert and his party know, the only means of slaying Emperor Evulz's hordes, and they have no reason to assume Evulz's knowledge of their plan.
Alternately, letting Emperor Evulz steal the sword is a very bad thing, since Albert and his companions have no way of slaying Emperor Evulz's hordes. However, one of Emperor Evulz's minions is destined to destroy the Eldritch Abomination that plans to devour the world. If Albert and his party had destroyed Emperor Evulz's minions before the Eldritch Abomination could be stopped, they would have left the world utterly defenseless against the Eldritch Abomination. Albert and his companions still have to get the sword back, since Emperor Evulz still has every intention of conquering the world, but at least now their world won't be a demonic god's supper.
The sword was cursed and backfired on Emperor Evulz just as he started to use it.
The party killed that minion in the process of taking the sword before the Eldritch Abomination even appeared.
Albert mocked Emperor Evulz while waving a ring that neutralize the curse in laughter. Evulz takes the ring and equips it.
Parodied: Albert, exploring the ruins hiding the sword, is shouted at by Evulz's minions, bored with his slow progress, who are waiting by the entrance. When he emerges, they greet like old buddies and he happily gives them the sword.
Having the hero responsible for the Eldritch Abomination's appearance provides him with a good and believable motivation to risk life against such a mighty foe.
Lampshaded: Albert, robbed of the sword by Emperor Evulz's minions, sighs that he could have seen it coming.
Invoked: Emperor Evulz deliberately spread the tales of the Dragon Breaker Blade and monitored the ruins where it most likely were concealed, knowing that many would-be heroes would kill themselves trying to find the weapon — and once someone did, he could have his forces sweep in and steal it.
Exploited: Asterwards, Bob convinced the king that he is a better hero than Albert.
Defied: "No way am I going for this Dragon Breaker Blade and let Evulz get it!"
Discussed: "So, we're going to get this sword?" "Uh huh..." "And what exactly will prevent Evulz from stealing it from us?" "Well... <whisper whisper>"
Conversed: "Have you noticed how heroes always need to find some MacGuffin only to have it stolen by the bad guy?"
Deconstructed: Albert has a massive Heroic BSOD upon learning that all their efforts just made the situation worse. It severely shakes his faith in himself and their chances of defeating the Emperor, and he has to rebuild his confidence before they can move on.
Reconstructed: However, this also makes him more determined to defeat the Emperor once and for all.
Played For Laughs: The quest for the sword is played out in Monty Python-esque style with heroes bickering about how it's going to be stolen, while Emperor Evulz is comically inept and has to rely on even dumber heroes to further his schemes.
Played For Drama: In trying to stop Emperor Evulz, Albert accidentally helps bring about the sort of destruction he was trying to prevent.