Despite obvious disadvantages, the characters frequently use the object, ability, or character least suited to the encounter.
Name Space: Main
Page Type: Trope
Yes, her element is ice, yes, that's a volcano behind her. And yes, she chose to fight here.
Let's say you, the average fire mage get into a bit of a scuffle and find yourself in a duel to the death. Don't worry, it's not your fault really, but you don't really have a choice here. Now you, being a fire mage, know that you happen to be very well versed in the art of using fire, you may even say it's your lifeblood, your modus operandi so to speak. You know the intricacies of fire in and out. Your opposing duelist allows you to select between several locations to have the duel. You can choose the fiery volcano, the dry, arid, hot desert, or the bottom of the ocean. Which do you pick? The ocean of course!
Wait... what? This trope is when, for whatever reason, the characters insist on using the most illogical matchup possible, like using the fire hose on the water mage, or the ice princess in the volcano field. Now sometimes this may be justified if, say, the person, despite having a disadvantage has some other good reason to fight them. This may include wanting revenge, having an intimate knowledge of the opponent, despite being weak to his element (say, two water mages fighting each other, despite them being resistant to each others attacks), or just because even though they're at a type disadvantage they outclass the opponent in sheer strength and experience.
For it to be this trope, there should also be some better alternative; if the mage decides to use water spells on the ice elemental, despite having fire spells at his disposal, it's this trope. On the other hand, if the mage who only has water spells is forced into fighting the ice elemental, and has no other options or items that would be better to use, it's a poor matchup; however, since they were forced, it didn't require any ignorance or poor planning (except maybe bad life planning finding himself in a situation with an ice elemental) and is therefore not this trope.
This also may provide an excuse for writers to allow the character to overcome adverse conditions and show growth when they win a very difficult battle from their sheer disadvantage, but often comes off as a cheapened experience, since more often than not the audience is left saying, "well, that's great! But why didn't they just pick the other guy?" Especially when their hard counter (or the fool they accidentally sent in) is someone with a definite theme any blind idiot could divine like Poor Predictable Rock. If a team does this and during combat they realize their mistake, this may lead to an Opponent Switch.
Note that for Video Games, only list examples in the story, or notable exceptions, such as games where choosing to fight with the worst counter is secretly the best option. Otherwise every game with Elemental Rock Paper Scissors will be on here, since with any game with type matchups, the player can deliberately make bad choices.
[[folder:Anime & Manga]]
In Marchen Awakens Romance, the characters have a habit of making fairly poor matchups in general. For instance, having the plant user fight the plant user in the final round of the War Games (to be fair, the others had their own grudge matches, and it worked out for revenge anyway). However, possibly the most blatant was picking Princess Snow to fight in the desert and volcano fields, while neglecting to use her either of the times they fought on the ice field.
The Pokemon anime (or at least Ash) has a habit of doing this, occasionally drifting into the need of a Deus Ex Machina or plot powers to resolve the situation, despite the fact that, say, Pikachu is clearly not the Pokemon for a given situation. The first gym battle in Black and White even mentions this, saying that Pokemon isn't only about type matchups, but friendship and strategy and whatnot.
Inverted in Bastard!!!, where the protagonist fights a fire elemental with fire spells, who comments on the stupidity of it, and how he should try ice spells... and then he turns the fire spells Up To Eleven and out heats the elemental, forcing it to swear loyalty to him.
In DodgeballThe Obi Wan tells them to attack their opponent's strengths (rather than their weakness), because it's unexpected and the opponent will have planned defenses for his weakness but not for his strength.
In the animated Teen Titans, when fighting Trigon, the team is forced to fight their Evil Counterparts. They each try and match them, to no avail, trying and failing for a good amount of time, until they finally reach a brilliant conclusion: switch who they're fighting so that they're, y'know, not fighting the one that can match their every move blow for blow.
In an episode of Captain Planet And The Planeteers, the heroes are trapped behind ice, but never think to use fire, despite elemental typing pretty much being their only means of problem solving as it is.
The main character's older brother does this in A Hero Born, when the three brothers are competing in matches of their own choosing, by choosing the main character's strongest subject to challenge him in. It later turns out he was intentionally throwing the competition.
In The Princess Bride, Inigo Montoya always uses his left hand for combat, except for the fact he's secretly right handed.
In Tales Of Symphonia, characters in a battle will remark if you're using an element poorly suited to the situation, like if you're hitting a Water-elemental monster with the Aqua Edge spell. Star student Genis will even get a title if he does this enough times in a single battle.