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SI Prefix Name

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SI prefixes are those used by the International System of Units for standard measurement. They are used to scale base metric system units of measurement like meters and grams, and go all the way from yocto (10-24, or one-septillionth, denoted with 'y') to yotta (1024, septillion, denoted with 'Y'). For example, a kilogram is 103 or 1000 grams.

This trope is in play when at least two SI prefixes are used to denote relationships between two things (Spell Levels, power tiers, size, characters, upgraded equipment, you name it). It also allows works to look a little scientific and insert a Sci Fi Name Buzzword or two. Handily, many of these prefixes are frequently encountered in real life, so one can reasonably expect the audience to understand that something named Giga (109) is bigger or stronger than a version of it named Mega (106) or Kilo. Likewise, Nano (10-9) is smaller or weaker than Micro (10-6) or Milli (10-3), even if not by those exact magnitudes.


Subtrope of Tiered by Name; compare Greek Letter Ranks.


Anime and Manga

  • Accel World: Ash Roller refers to luck in SI prefix terms. He generally calls people "Mega" or "Giga" Lucky/Unlucky but those in particularly unfortunate circumstances might be referred to as "Tera-Unlucky".
  • Beast Wars II: Galvatron's second-in-command Megastorm got a Mid-Season Upgrade into Gigastorm.
  • Kuro's Signature Attack in Black God is tiered by SI prefixes: Mega-Exe, Giga-Exe, and Tera-Exe. The last one requires combining the powers of the three main characters.
  • Kaguya-sama: Love Is War: Terashima is originally nicknamed "Terako", but then got demoted to "Gigako", and later "Megako".
  • In Guyver, the Megasmasher can be upgraded to the powerful Wave-Motion Gun Giga-Smasher.



Video Games

  • Chrono Trigger: The Black Omen has a series of bosses named the Mega Mutant, Giga Mutant, and Tera Mutant. They behave very similarly and look identical, but each one is stronger than the last.
  • Digimon: Subverted by Gigadramon and Megadramon, whose power levels are...exactly the same.
  • Disgaea
    • The franchise uses SI prefix names to denote spell tiers after the base spell, starting with "Mega" and ending usually with either "Omega" or "Tera". Some of the Updated Rereleases include "Peta" as a final tier.
    • Makai Kingdom: The game's main character and Badass Freakin' Overlord is named "Zetta". When the Updated Re-release gives Zetta a daughter, the game keeps the Theme Naming by giving her the name "Pet(t)a".
  • Dustforce has a series of bonus levels, the Difficults, named from Kilo to Exa. (eg. "Giga Difficult").
  • Final Fantasy:
    • The recurring summon Bahamut has attacks based on the word "Flare" and some big SI prefix. The most common is Mega Flare, but some games have advanced versions of Bahamut capable of "Giga Flare", "Tera Flare" and so on.
    • In Final Fantasy XIII, there's a monster called Microchu and a stronger version called Picochu.
  • Pokémon: The Life Drain move Mega Drain, itself a stronger version of Absorb, has an even stronger version named Giga Drain.

Western Animation

  • ReBoot has Gigabyte, who is eventually split into Megabyte and Hexadecimal.