Death By Stupidity

The aliens (if they were indeed aliens) were allergic to water, yet they went to a planet loaded with water.

At least half of the deaths in this TV show are due to stupidity, often combined with alcohol and/or drugs. 1,000 Ways to Die is a show that makes Natural Selection hilarious!

Death by stupidity on a massive scale!
Using an energy drink with electrolytes to water crops?

Any of Stryker's forces who keep shooting at Wolverine count. If they were smart, they would have put down their weapons and walked away.

You would think that Belloq, at least, would have done his homework about the Ark. Those who have seen the movie know what happened to him and the Nazis who were with him.

Why, exactly, did Schultz shoot Candie when he did? It was an incredibly stupid thing to do and it almost got Django killed, too.

Amanda (Katie Cassidy) tells Peter, who she doesn't even know, that she and Kim would be alone in the apartment. Why didn't she give him a key while she was at it? Her stupidity makes it really hard, if not impossible, to have any sympathy for her.

This one is debatable.

Mills gives Murad, the Albanian mob boss, a chance to walk away. Instead of walking away, Murad tries to kill Mills, which turns out to be suicide.

Murad's decision seems pretty damn stupid, but I'm not sure if this one counts as stupidity. Albanian culture has the traditional code of laws called the Kanun. In the Kanun, revenge is considered a duty. If Murad did walk away, he would have lived with dishonor for life.

Tommy DeVito (Joe Pesci) kills Billy Bats - a made guy. As a guy with mob connections, he should have known that killing a made guy is tantamount to suicide.