What happens when The Glorious War of Sisterly Rivalry switches genders? Cain and Abel. What's the difference between The Scrappy and a Creator's Pet? Authors love their Pet. Is this introductory paragraph trying to explain by example a Xanatos Gambit or a Batman Gambit? When defining a trope, it often helps to establish its similarities, differences and relationship to other tropes; a common convention on this site is to refer to some tropes as Sister Tropes. When two or more tropes have some overlap in their descriptions, "parentage", or use, but not enough for one to be a Sub-Trope or Super Trope of the other, these are called Sister Tropes. That is, both have a similar form or function, either by category (character, plot) or by effect (characterization) rendering them both similar but distinct enough to be considered equals. Not that there's anything wrong with subtropes! These are the four Trope Sisters, each more lovely than the last:
- Function: When two or more tropes serve the same function, but are notably different in execution.
- Form: When two or more tropes are similar in style but themselves unique, usually used for different purposes.
- Same Parent: Subtropes of the same Super Trope are frequently referred to this way.
- Conjoined Use: They are different, perhaps a character and an attack, plot, or relationship, but see frequent (though not necessarily exclusive) use together.
- It is possible to juggle a Villain, Idiot and Conflict Ball all at once. Idiot Ball doesn't necessarily make direct conflict, and Conflict Ball doesn't necessarily make idiocy. Thus they are related, but not really covered by the other. Villain Ball carrying may involve stupidly Pyrrhic Villainy and cause conflict aplenty, but it doesn't have to.
- Big "NO!" and Chewing the Scenery (or Large Ham) can often overlap, but not always.
- Impractically Fancy Outfit is a cause of the Ermine Cape Effect, but the latter trope is also responsible for the continued application of the former.
- Royals Who Actually Do Something and Lady of War occasionally overlap, as royalty is generally expected to look elegant at all times.
- If a Lethal Chef prepares a meal for you, chances are It Tastes Like Feet.
- One Judge to Rule Them All and Golden Snitch are sister tropes, as both are about a single condition that renders all other factors in a contest irrelevant.
- So are Gargle Blaster and Hideous Hangover Cure. One is the cause of hangovers, while the other is the cure, but both are absolutely outrageous.
- Cast of Snowflakes is what happens when those Loads and Loads of Characters are given characterization.
- Nice Job Breaking It, Herod!, your Genocide Backfired on us completely.
- Human Shield and Bulletproof Human Shield both deal with bystanders being used to protect a target. The former discusses the psychological coverage, while the latter deals with physical protection.
- Evil Twin, Evil Counterpart, Evil Knockoff, and Criminal Doppelgänger are all about evil duplicates of one person, but the evil persona in the individual tropes are an identical twin, a persona from an Alternate Universe, an intentionally created duplicate, and an Identical Stranger, respectively.
- Descending Ceiling and The Walls Are Closing In are both Death Traps that threaten to squash/crush characters trapped in them, but have different parts of the room move to achieve this.
- The Ace and Parody Sue are closely related concepts with different intentions and execution. Both are (usually) played for comedy, but while the former is an idealized character whose over-the-top nature is played for laughs, the latter is a Take That against a fandom in general.
- Innocent Fanservice Girl and Shameless Fanservice Girl. Both are girls who have no nudity taboo. But one is aware of the existence of nudity taboos, and the other isn't. Both are also sisters to the Reluctant Fanservice Girl; while all three generally end up exposing a lot of skin, the first two do so willingly, while the last only does so because the Universe conspires to leave her naked at the worst times.
- Badass Normal and Non-Powered Costumed Hero often overlap in certain contexts (most importantly probably the person of Batman), even though the only thing they conceptually have in common is having no superpowers.
- Xanatos Gambit and Batman Gambit are both schemes to achieve benefit but they are executed differently. The Batman Gambit is based on Flaw Exploitation and/or what a given mark is most likely to do. Thus, it will fail if the mark doesn't behave as predicted. The Xanatos Gambit is based on Morton's Fork: it can succeed no matter which prong the mark is impaled on. The benefits may be completely unrelated or they may be different paths to the same goal as long as every reasonable outcome benefits the planner in some what.
- Unnecessarily Large Vessel regularly goes hand-in-hand with Starship Luxurious. The main distinction is that Starship Luxurious refers to the spaces inside the ship being much larger and fancier than is strictly necessary, while Unnecessarily Large Vessel refers to the ship itself being bigger than it needs to be.
- Boarding Pods and Drop Pods are both for getting troops from a ship to a target in a surprising fashion. The difference is the target: drop pods are launched onto a planet surface as a futuristic version of It's Raining Men, while boarding pods are fired at other ships or at stations to deploy a Boarding Party.
- Passed In Their Sleep and Slain In Their Sleep.note Both deal with death by sleep, but while Passed In Their Sleep is more peaceful, Slain In Their Sleep...well...
- "Why Are You Looking at Me Like That?" "Because you just Got Volunteered."
- A victor indulging in Unsportsmanlike Gloating and the defeated party being a Sore Loser are diametric opposite responses based on whether one is victorious or defeated. They are also often conjoined, in that it's very likely for a Unsportsmanlike Gloater in victory to be a Sore Loser in defeat.