History Main / CastFromExperiencePoints

* ''TabletopGame/VampireTheRequiem'' has a few of the most powerful Theban Sorcery spells cost Willpower Points; once cast, the stat ''itself'' goes down. Characters can spend XP to buy it back up to the previous level, but until then they're essentially less able to expend mental and emotional energy. Interestingly, creating a new vampire requires the exact same expenditure on part of the vampire's sire. The setting details some sires who mass embrace too many, too quickly, and become emotional wrecks unable to hold themselves together.
* ''TabletopGame/PrincessTheHopeful'': As with Vampire above, a few of a Princess's most powerful Charms (most notably crafting a Bequest or empowering someone as a Sworn) cost a dot of Willpower, which must be bought back with XP.

!!Folders

[[folder:Anime and Manga]]
* In ''Literature/Overlord2012'', some of Ains' most powerful spells, such as Memory Manipulation and Wish Upon a Star, are noted to be cast from his EXP rather than his MP. This makes him reluctant to use them, as EXP is much harder to come by in the New World than it was in ''YGGDRASIL''.

[[folder:Fan Fiction]]
* In ''FanFic/HarryPotterAndTheMethodsOfRationality'', several spells are powered by Sacrifice, including Fiendfyre, which permanently decreases your blood volume, and the Unbreakable Vow, which permanently decreases someone's Magic reserves (thus explaining why it's not routinely used to enforce business deals).

[[folder:TabletopGames]]
* ''TabletopGame/DungeonsAndDragons''
** In 3e crafting magical items costs XP, with powerful spells like "Wish" and "Miracle" also costing XP.
** In 3.5, the following spells require XP: [[http://www.d20srd.org/srd/spells/planarAllyLesser.htm Planar Ally]] (all spells), [[http://www.d20srd.org/srd/spells/atonement.htm Atonement]], [[http://www.d20srd.org/srd/spells/commune.htm Commune]], [[http://www.d20srd.org/srd/spells/restorationGreater.htm Greater Restoration]], [[http://www.d20srd.org/srd/spells/gate.htm Gate]], [[http://www.d20srd.org/srd/spells/miracle.htm Miracle]], [[http://www.d20srd.org/srd/spells/awaken.htm Awaken]], [[http://www.d20srd.org/srd/spells/permanency.htm Permanency]], [[http://www.d20srd.org/srd/spells/vision.htm Vision]], [[http://www.d20srd.org/srd/spells/simulacrum.htm Simulacrum]], [[http://www.d20srd.org/srd/spells/limitedWish.htm Limited Wish]], and [[http://www.d20srd.org/srd/spells/wish.htm Wish]].
** The 1st/2nd Edition compatible supplement ''The Tome of Mighty Magic'' has a spell called Divine Retribution. If the spell fails, it drains a [[CharacterLevel level of experience]] from the caster.
** The 1st Edition spell Energy Drain. There is a 5% chance the caster will be drained of a [[CharacterLevel level of experience]].
*** Energy Drain returns in later editions as a debuff, in the form of negative levels. At first, energy drain inflicts a temporary [[LevelDrain negative level,]] sapping hit points and inflicting a 1:1 penalty to all rolls and statistics. If this level isn't removed, and the save against it is failed the following day, the negative level may become permanent, forcing the hapless character to earn their level back the hard way.

[[folder:VideoGames]]

[[folder:WebComics]]
* ''WebComic/TheGodOfHighSchool'' features a character who essentially does this, manifesting as aging in reverse when she uses her powers. Essentially she turns into a child, or could even de-age out of existence if she doesn't wait years between using her abilities.
* ''Webcomic/TheOrderOfTheStick'': a ''TabletopGame/DungeonsAndDragons''-inspired RPGMechanicsVerse, has occasional references to XP costs.

** Redcloak refers to the XP cost of a [[https://www.giantitp.com/comics/oots1264.html Gate]] spell as "draining a little bit of my soul."

[[folder:WebOriginal]]
* In ''MaouTheYuusha'', an overlord creates servants from their own essence, decreasing their own stats in the process. Most Overlords send their servants out to level, then reabsorb them, gaining a net XP increase.
* In AgainstTheGods, [[DangerousForbiddenTechnique Forbidden Techniques]] are fueled by Heart's Blood, something which typically causes the user's Cultivation Level to drop.

* In ''LightNovel/Overlord2012'', some of Ains' most powerful spells, such as Memory Manipulation and Wish Upon a Star, are noted to be cast from his EXP rather than his MP. This makes him reluctant to use them, as EXP is much harder to come by in the New World than it was in ''YGGDRASIL''.

* In ''Webcomic/TheOrderOfTheStick'', a ''TabletopGame/DungeonsAndDragons''-inspired RPGMechanicsVerse, Vaarsuvius [[SureLetsGoWithThat lets Durkon believe]] that Vaarsuvius cast a spell with a high XP cost to gain an incredible HourOfPower, hence why it [[https://www.giantitp.com/comics/oots0667.html can't be repeated.]] In fact, the power boost came from [[spoiler:a DealWithTheDevil.]]