Idiot Ball

Obi-Wan: Wait a minute. How did this happen? We're smarter than this.

Anakin: Apparently not.

—Star Wars Episode III: Revenge of the Sith

A moment where a character's stupidity fuels an episode, or a small plot line. If multiple characters have the Idiot Ball it becomes an Idiot Plot. Temporary (or permanent) Genre Blindness is often a cause of this trope.

Coined by Hank Azaria on Herman's Head: Azaria would ask the writing staff, "Who's carrying the idiot ball this week?" This is generally not a compliment on the writing because the person carrying the idiot ball is often acting Out of Character, misunderstanding something that could be cleared up by asking a single reasonable question or performing a simple problem-solving action, but that he isn't doing solely because the writers don't want him to. It's almost as if the character is being willfully stupid or obtuse.

Unsurprisingly, this provokes a What an Idiot! response from the audience. However, sometimes, the purpose is to help the audience. Sometimes, the holder of the idiot ball asks the dumb question to allow a certain amount of exposition to occur that wouldn't organically be talked about, but needs to be stated for the audience.

On the other hand, making stupid mistakes can be the hallmark of Character Development if the person recognizes it in the end. Seeing someone discarding the idiot ball can be a rewarding moment when they are Taught By Experience.

See also Villain Ball, Hero Ball, Distress Ball, Idiot Plot, Forgot About His Powers, Alcohol-Induced Idiocy, Comedy of Errors, Too Dumb to Live, What an Idiot!, Conflict Ball, Bullying a Dragon, Mugging the Monster, Failed a Spot Check, Ping-Pong Naivete, Third-Act Stupidity *big breath* , and Out-of-Character Moment. A Stupidity-Inducing Attack is essentially what happens when a character deliberately throws the Idiot Ball at another character.

This trope is the Opposite Trope of Smart Ball, and probably not closely related to Sanity Ball, Happy Fun Ball or Advantage Ball. And not even remotely related to the Timey-Wimey Ball.

Related "forgetfulness" tropes:

Character Condition	Character doesn't remember, or Remembered Too Late	Character remembers, maybe Just in Time
Has magical or metahuman ability	Forgot About His Powers, Reed Richards Is Useless	Remembered I Could Fly
Has mundane ability	Idiot Ball	Forgot I Could Change the Rules
Doesn't have mundane ability	Forgot I Couldn't Swim	?

Examples of Idiot Ball are listed on these subpages:

Examples of Idiot Ball include:

Professional Wrestling

After a rift with Arn Anderson, Ric Flair recruited Sting to be his partner in a tag match against Anderson and Brian Pillman at WCW Halloween Havoc 1995. Sting accepted. Then, as soon as he tagged Flair, he got himself an old-fashioned Horseman Beatdown.
Lex Luger carried it frequently in his WWF stint, but the worst instance of them all was when he had to fight off rumors of selling out to Ted DiBiase. The loudest voice of said rumors happened to be Tatanka. The two faced off at Summerslam 94 with the Native American coming out on top. After the match, Luger still couldn't figure out what the Million Dollar Man had to do with this.. until Tatanka beat him up post-match.
Randy Savage carried it in the 1993 Royal Rumble. After dropping his flying elbow on Yokozuna, he went for a pinfall. Problem is, pins do not count in a Royal Rumble match. Yoko powered out of the pin, sent the Macho Man over the top, and secured a WWF Championship match at Wrestlemania IX.

Web Animation

Coach Z on Homestar Runner. It seems that he only keeps his "more than two praeblams" (other than his butt fixation) for one episode. The whole cast plays dodgeball with the proverbial Idiot Ball.
- The titular character IS an Idiot Ball, which is really almost the point of any short with him in it.

Web Original

v4 of Open Blue's Backstory has King Armando of Avelia betting his country's second largest colony in a swordfight with the greatest swordsman in the Old World. Naturally, he lost. For a skilled diplomat and peacemaker, Tempting Fate like that wasn't exactly a pretty smart thing to do.
Whateley Universe example: during the "combat finals" at Whateley Academy, Buster (super-strong brick who gets stronger and tougher the more you hit him) drew Aquerna, one of the school losers. He lost by chasing her all over the place until she found a spot where she had the advantage. Lampshade Hanging by the instructors, who pointed out that he was so much stronger than she was, all he had to do was go to the 'win spot' and type in his answers, and she wouldn't have been able to do a thing to stop him.
Cracked.com's 6 Movie Plots Made Possible by Bafflingly Bad Decisions.
- Then again, If Movie Characters Didn't Make Horrible Decisions movies would be much less fun.
In Netland VII, when Taricus decides to attack the Sarin canister, thereby killing everyone except Tyberix (who has a built-in rebreather).

Real Life

There is a whole website about people who managed quite impressing feats of stupidity. Quite honestly most of the following examples look pretty harmless in comparison.
Bernie Madoff ran an elaborate Ponzi scheme for years. The SEC was repeatedly given tips and warnings over the years, but completely failed to discover the massive fraud. He was only stopped when his own SONS turned him in.
Anyone who starts a riot in a scene with a tense atmosphere. Seriously, who comes across one of those and thinks "Wow, this could use some violence!"
- The thing about mobs is that they become collective idiots.
- Villains can manipulate mobs that way.
HBGary was a very important and security company, so much that the founder wrote the book on rootkits and it worked for the federal government and big corporations. Yet somehow, when Anonymous hacked one of their employees and then the whole company, it was evident that HBGary had made tons and tons of security mistakes that are dealt with in even a beginner's book. Unable to suspend your disbelief? Read this arstecnica article. The hindsights made in HBGary are so hard to believe that some people in the security world are speculating that maybe HBGary were acting as some kind of Honey Pot to trap Anonymous later.
World War I: For the Battle of Neuve Chapelle in 1915, the British very carefully calculated exactly how much artillery fire they would have to apply over how long in order to break through the German defences. They picked up the Idiot Ball after that, though, hardly even bothering to do the same calculations again until much later (with predictable results). To be fair, by the time they were running assaults on the scale of the Somme, the pre-war arms industry hadn't grown enough to supply them with enough shells and they had to settle for firing off everything they had and hoping it was enough (which it too often wasn't). Later, when they had all they wanted and could break any German defence system at will, they handed the idiot ball to the Americans... who refused to learn from experience and were determined to reinvent the wheel.
Adolf Hitler grabbed the idiot ball during the later years of World War II and hung on for dear death.
In the NHL, if a team pulls the goalie in overtime, they lose the one point they would normally acquire after forcing OT. Los Angeles Kings coach (at the time) Andy Murray pulled Cristobal Huet to bring in the extra attacker in a late season game against the Columbus Blue Jackets. Andrew Cassels scored the empty netter, and the Kings lost that overtime loss point.