Damsel in distress

The damsel-in-distress (acronym DiD) is a timeless motivation wherein a girl is put in a dangerous situation where she cannot escape on her own and requires a male hero to rescue her. Princesses, girlfriends and sisters are often put in this role.

Not to be confused with princess and dragon, which is a subcliche, mind you.

So how does it work?
The girl can be put in distress in these ways;
 * kidnapped and held prisoner
 * get possessed/brainwashed
 * chased and attacked by/transformed into a dangerous monster/animal
 * get caught up in a natural disaster
 * cursed to die in some way
 * be trapped somewhere
 * be threatened in a way that could lead to her death

Examples
Bold indicates that I invented the character and/or media.

Literature

 * Cassie Mifsud from Oliver Galaxy
 * Christine Daaé from The Phantom of the Opera 
 * Jaiden Gundersen from Titan Troop 
 * Penélopê from The Odyssey 
 * Poppy from Club Hour 

Films

 * Beverly Marsh from IT (2017)
 * Ginny Weasley from Harry Potter and the Chamber of Secrets
 * Jenny Foxworth from Oliver & Company 
 * Maid Marian from Robin Hood (1973)
 * Marion Ravenwood from Raiders of the Lost Ark 
 * Megara from Hercules (to be fair, it was a Mario parody)
 * Penny from The Rescuers 

TV

 * Bubblegum from Adventure Time (original mini-movie and first season only)
 * Connie Maheswaran from Steven Universe (put in danger numerous times)
 * Daphne Blake from Scooby-Doo (who's been kidnapped more than Kenny's died)
 * Raven and Starfire from Teen Titans (Raven was attacked in The Beast Within; Starfire was kidnapped in Sisters)
 * Raven Corvus from South Park (especially in the Mysterion fanfics)

Video games

 * Amy Rose from Sonic
 * Krystal from Starfox Adventures 
 * Palutena from Kid Icarus 
 * Peach from Super Mario Bros 
 * Zelda from The Legend of Zelda

Trivia

 * Emma Watson hates this motivation because she thinks it spreads the fact that "girls are helpless and need boys to help them" and she's doing everything in her power to prove that's not true.