Readers of romance use the term "too stupid to live" (TSTL) to describe a character, usually the heroine, who does incredibly dumb things to further the plot.
These characters are equivalent to the scantily clad bimbo in a horror movie who leaves a locked house to wander around outside bellowing, "Is anyone there?"
Of course, the really stupid or lazy person is the author who didn't bother to create a logical plot.
You're not sure if the heroine is too stupid to live? Here are some examples.
A heroine may be too-stupid-to-live if she
Doesn't change her lock or improve security after a serial killer breaks in her home and leaves a threatening note. Nor does she consider staying elsewhere.
Sends her guards home after the so-far-inept police decide they have captured the serial killer.
The heroine gets hot for the hero and does something about it when the bad guys are near.
The trained assassin is sneaking up on her professional bodyguard so the heroine, with no fighting training, attacks him herself rather than yelling a warning.
The "Full Moon Killer" is savaging locals. The creepy guy next door reeks of Nair, wears flea colors, and buys large boxes of Milk Bones although he doesn't own a dog, but the heroine isn't suspicious because "werewolves don't exist."
The heroine has an entire troop of bad guys after her, but she doesn't call in reinforcements, seek help from the police, or tell the hero she's in trouble.
She has the only copy of some incriminating documents, and she doesn't make copies, or put them in a safety deposit box in her bank. Instead, she leaves them in her apartment. Under the bed.
The heroine's blind date drinks really red Bloody Marys, has a bad overbite, and stares at her jugular vein instead of her large boobs, but she isn't suspicious because "vampires don't exist."
The bad guy asks her to meet him to exchange the documents for the hero, and she goes without back up or a weapon.
Bad guys are after the heroine so she picks high heels instead of running shoes because she'd rather die than be unfashionable.
The heroine starts a verbal battle with the hero while they are trying to sneak up on the bad guys.
Someone is trying to kill her so she wanders around outside and in the cavernous mansion she’s staying at.
What can you do to avoid a TSTL character? If you need your stalker-chased heroine to appear on national TV, don’t have her on the kiss cam at a nationally televised football game. Instead, have her save a child from a burning car, and the rescue is caught by someone with a cellphone. If she must do something stupid, have her know that it is stupid or dangerous yet make all other options worse or impossible.
As Forrest Gump said, “Stupid is as stupid does.” This applies more to the writer than the character.