Tropes that surround twins (and higher-order multiple births — triplets, quadruplets, quintuplets, ad infinitum
- Alleged Lookalikes
Two characters look awfully alike to the cast, but the audience doesn't believe they're any different than anybody else.
- Always Identical Twins
When twins of the same sex are mentioned in fiction, they are almost always identical, not fraternal.
- Angsty Surviving Twin
One twin dies so the other can be angsty (and more unique).
- Backup Twin
Killed Off for Real? A twin or clone shows up from nowhere to pick up where you left off.
- Conjoined Twins
Conjoined twins are far more likely to appear in fiction than in real life.
- Coordinated Clothes
Twins—especially identical twins—in fiction will often wear identical (or stylistically similar) outfits to emphasize the twin factor.
- Creepy Twins
Single-Minded Twins, but with the creepiness factor played up.
- Evil Twin
Introducing...the evil(er) version of you!
- Fake Twin Gambit
Pretending to be one's own identical twin, whether such person exists or not.
- Fearful Symmetry
Identical combatants with identical attacks will cancel each other out.
- Finishing Each Other's Sentences
Due to Twin Telepathy or Twin Banter, twins can carry on one side of a conversation no matter which one is speaking.
- Half-Identical Twins
Brother-sister (i.e., fraternal) twins act identical in all ways other than sex.
- Identical Twin ID Tag
Twins make themselves distinguishable with hairstyles, costumes, or scars.
- Impersonating the Evil Twin
A character is pretending to be his Evil Twin, usually badly.
- Making Use of the Twin
If an actor has an identical twin, bring them into the cast!
- One Twin Must Die
When having twins is a sign of bad luck/bad omen, only one must live.
- Playing Their Own Twin
Twin or related characters are played by the same actor.
- Polar Opposite Twins
When the Odd Couple happen to be twins.
- Same-Sex Triplets
A set of triplets is more often than not all identical and of the same sex.
- Separated at Birth
Siblings (usually twins) get separated at birth and meet for the first time later in life.
- Sibling Seniority Squabble
Twins arguing over who has seniority due to being the oldest, even if it's a difference of minutes.
- Single-Minded Twins
They have identical appearance and personality and may as well be one person in two bodies.
Twins share injuries or other metaphysical traits.
- Tag Team Twins
Twins used as a tag team duo in Professional Wrestling.
- Theme Twin Naming
Twin names follow a theme: rhyme, alliteration, named after famous twins, etc. This is especially common with identical twins or at least twins of the same gender (boy-boy, girl-girl).
- Trickster Twins
A pair of twins who are up to no good.
- Think Twins
Two brains are smarter than one.
Twins getting it on with each other.
- Twin Banter
The snappy patter and unique speech patterns that twins form with each other.
- Twin Desynch
Twins start to look and act differently after they've been separated for a while.
- Twin Switch
Twins swap roles with each other, such as with a Two-Timer Date. Hilarity Ensues if they are Polar Opposite Twins.
- Twin Telepathy
Twins share a Psychic Link, from simple telepathy to full-on Synchronization.
- Twin Threesome Fantasy
What's hotter than a threesome? A threesome where two of them are twins!
- Two Siblings In One
A twin absorbs the soul, Life Energy, or other metaphysical properties of their deceased sibling.
- Unto Us a Son and Daughter Are Born
When twins are born in a series, and aren't just there from the start, they're almost always boy-girl fraternal twins.
- Weaker Twin Saves the Day
Where one twin is weaker but ends up reluctantly saving the day when his stronger brother dies.