Playing With / Murder the Hypotenuse

Basic Trope: Someone tries to kill a romantic rival to get them out of the way.
  • Straight: Alice poisons Claire's drink so she can have Bob all to herself. No one considers Polyamory viable.
  • Exaggerated:
    • Alice blows up Claire's apartment building just because Bob mentioned that a dress looked nice on Claire.
    • Alice wipes out the whole world so Bob will only have her.
  • Downplayed:
    • Alice puts sleeping powder in Claire's drink to temporarily incapacitate her, so Bob will take Alice to the dance. Claire is fine in an hour or two.
  • Justified:
    • In Alice's culture, the concept of Klingon Promotion applies to love interests too.
    • Claire kills Alice, but only in self-defense after Alice tries to kill Claire.
  • Inverted:
  • Subverted:
    • Alice plans to kill Claire, but stops at the last minute.
    • Turns out Alice isn't interested in Bob.
    • Turns out Claire isn't interested in Bob - Alice just misinterpreted. Further, it turns out Claire's actually interested in Alice (And is unaware of Alice trying to kill her).
    • Alice is sorely tempted to kill Claire and has a massive internal war between securing Bob for herself and not committing murder. She eventually realizes that if she kills Claire and Bob finds out, he'll hate her forever and she won't have him anyway, so she decides not to kill Claire.
  • Double Subverted:
  • Parodied:
    • Alice is all sweetness and smiles when Bob is looking, but keeps lunging for Claire with a knife the instant Bob turns his back.
    • Alternatively, Alice still lunges at Claire when Bob is looking, but she's lunging at her with a rubber inflatable sword that squeaks every time it hits. Because of this, Claire and Bob think that Alice is just kidding around and has a laugh about it.
  • Zig Zagged: Alice poisons Claire's drink, but then has second thoughts and tries to get the drink back, causing hilarity to ensue as they play Poisoned Chalice Switcheroo. They are interrupted when Bob enters the room and takes a sip from the drink himself, which is Played for Drama. It turns out, though, that you need to drink more than a sip for the poison to be noticeable, and Bob starts asking why Alice looked so upset. Alice, overreacting and failing to think of an excuse, drinks the whole thing herself while declaring "You'll never take me alive!"
  • Averted: Alice resolves to win Bob's heart by fair means. Or they become polyamorous.
  • Enforced: The writers want Alice out of the story, and having her get arrested for derailing herself seems the quickest way.
  • Lampshaded: "Did you see the look on Alice's face? I bet Claire is checking her drinks pretty damn carefully these days."
  • Invoked: Alice is encouraged to kill Claire by someone else who wants her dead.
  • Exploited: Alice tries to kill Claire, but Claire knew it was going to happen; so, she sets a trap in order to expose Alice's true face to everyone else, including Bob.
  • Defied: Alice deliberately avoids Bob and Claire so that she won't be tempted to do something she'd regret.
  • Discussed: "She should have been your first suspect. The jealous lover is one of the oldest ones in the book, aside from the Butler, of course."
  • Conversed: "The writers of this show seem to think that a woman can't be in love without it turning her into a murderer."
  • Deconstructed:
    • Alice succeeds in eliminating Claire and winning Bob's heart, but the strain and guilt soon cause her to have a breakdown, preventing her from getting any pleasure out of her prize.
    • Alternately, when Bob discovers what Alice did to Claire, he is horrified and immediately breaks up with/calls the cops on her.

Ha! Can't you see the link back to Murder the Hypotenuse loves me more than you? You had your chance and you blew it! Just grow up and accept—BLAM! BLAM!
http://tvtropes.org/pmwiki/pmwiki.php/PlayingWith/MurderTheHypotenuse