Percent-Based Values

One of the Role-Playing Game tropes.

Some items' effects are based on a set numerical value. This is when they're based on a percentage, like when an item heals 50% of someone's maximum Hit Points.

Usually, revival items also restore a character's hit points by a set percentage.

And items that fully heal a character would count as this, with the percentage being 100%. Also, if an item heals a character by the Cap of a certain value, that's count as this trope, even though it's not a stated percentage, since it would count as 100% healing.

Despite all the talk about healing items, buffs and debuffs would count as well, such as Meta Power Up and its sub-tropes.

An effect that happens under some percent of health would be Critical Status Buff, not this trope, since a value based on a percentage is not a part of that.

This trope covers Damage Over Time that bases itself on percentages of the afllicted's maximum Hit Points.

Super-Trope of Percent Damage Attack, which is this but for attacks that base its percentages on a target's current Hit Points.

---

Video Game Examples:

Action RPG

• Chantelise: The game's use of Equipment-Based Progression, which technically increases Elise's stats by a fixed value, but since there's no way to change her stats otherwise, items effectively give percentage increases to her stats, throughout the whole game.
• CrossCode: All of the consumable items have an effect that's expressed in the form of a percentage. For example:
  • The Chef Sandwich will restore half of Lea's HP.
  • The Chili Dog will temporarily increase Lea's Attack and Focus stats by 15% each.
• Honkai Impact 3rd: With certain exceptions, many attacks - whether normal ones, weapon skills or Ultimate Skills - go by a percentage of the user's Attack stat.
• Titan Quest: Boosts to stats from items, can be based on percentage of the character's initial value of that stat, like a 9% Strength boost.
• Tofu Tower (Naka): Traps deal 5% of Tofu's Maximum Hit Points when stepped on, rounded up.

Eastern RPG

• Born Under the Rain: The potions, with the percent being 100%. A Healing Potion "Fully heals an ally.", while a Mana Potion "Fully restores an ally's MP."
• The Boxxy Quest series: The Virus condition does [1% of Max Health] of Damage Over Time every 3 steps, when out of battle:
  • BoxxyQuest: The Shifted Spires
  • BoxxyQuest: The Gathering Storm
• Epic Battle Fantasy: In multiple games:
  • Epic Battle Fantasy 1:
    • Matt's various swords he can switch between, as said in their Help section, such as:
    • Devil's Sunrise:

      Atk -30%
      Def +10%
      Matk +10%
      Mdef +10%

    • Blood Blade:

      Def +10%
      Mdef +10%

    • In the items menu, it's said that:
    • Attack Potion:

      Boosts Attack by 50%

    • Magic Potion:

      Boosts Magic Power by 50%

  • Epic Battle Fantasy 4: For equipment's effect on stats, and after the Battle Mountain update, some healing items' effects. For example, this piece of equipment: Flower Pot: At level 1, it boosts physical and magic defenses by 5%, and stops 10% of Thunder and Earth, damage.
    • Healing items:
    • Crisps: Heals all living party members for 25% of their max HP.
    • Chips: Heals all living party members for 50% of their max HP.
  • Epic Battle Fantasy 5: All healing items, and the buff and debuff statuses. The listed values are the base, which can be boosted with certain equipment, which also increase their wearer's abilities by percentages:
    • Healing Items: Such as Pumpkin: "Heals an ally for 300 HP, or 20% of their max HP. Whichever is higher."
    • Status Buff items: Such as Beer: Buffs an ally's attack by 60%.
    • Equipment: Such as Fusion Blade: At level 1, it boosts Physical and Magic attack by 15%, and blocks 10% of Bomb, Fire, and Bio damage.
• Eternal Senia: Hydrangea After The Rain: Multiple skills:
  • Phantom Strike variants:
    • Mana Economy is a Reduced Mana Cost ability that removes the mana cost of the skill.
    • Phantom Lightning gives double damage for the skill if it's used to dodge an attack.
    • Infinite Phantom removes the cooldown of the skill.
  • The Continuous Tear version of Lightning Tear, "Leaves a whirlwind that inflicts 8 x 30% dmg/s for 15s. Increased cooldown."
  • The Fairy Helper skill variants, as a base, restores 30% of Senia's Hit Points when used:
    • "Fairy Strike" sacrifices that base, for the Little Fairy to Headbutt enemies for 3000% some combination of base, and sword damage.
    • The "Elixir of Perseverance" adds an effect to cut damage taken, by "25% for 10 s"
  • Eternal Awakening's Eternal Barrier variant reduces the damage of the next blow received by 75%.
• Final Fantasy: Across multiple entries of the series:
  • The recurring Ultima Weapon, from the third game onwards, and extending to the remakes of the first and second, is a special sword that deals damage proportionate to how much health you have remaining. When you're topped up, it's by far the most powerful weapon in the game. When you're low on health, it does piddling damage.
  • In Final Fantasy VI, the Step Mine spell deals damage equal to 3.1% of the total steps your party has taken throughout the game, up to 9999 HP. Furthermore, its MP cost is also equal to 3.33% of the number of minutes you've been playing the game, up to a maximum of 255 MP.
• Golden Sun:
  • Every restorative Djinni works off of a percentage. Spring heals someone for 70% of their max HP, Spark may revive someone at 60% of their max HP, and Wisp restores 10% of everyone's max PP, among many others.
  • All stat buffs and debuffs that affect attack, defense, and agility also operate on percentages. The Impact spell increases someone's attack rating by 25%, while the Mercury Djinni Foam will cut all enemies' agility in half.
  • Summon Magic attacks factor the target's maximum health into the damage calculation. They all have a base elemental power similar to regular Psynergy, but they're also guaranteed to hit your target for anywhere from 3%^note the one-Djinni summons like Mars or Jupiter to 40%^note Iris, received as a reward for defeating the game's strongest superboss of their max HP.
• The Haunted Ruins: From the manual given on the game's page:
  • Meat: Restores 1/4 "HP."
  • Magic Meat: Restores 1/4 "MP."
  • The Recov spell: "Restores 1/2 "HP."
  • The Boost spell: "Increases power of next attack by 3x."
  • Poison: "When poisoned, you will lose 10% "HP" with each step."
  • "When HP goes to zero, you lose half your money."
• Jimmy and the Pulsating Mass: Multiple:
  • The Ants on a Log restore "50% of max HP".
  • Buck's Nerd Bash skills, are presumably basing their percentages off the standard Attack commands:
    • Bully does 150% physical damage
    • Mag Combo does "300% physical damage", with a "two-turn cooldown".
    • Inner Rage boosts the ATK stat by 50%, while removing player control of Buck.
• Oracle of Askigaga:
  • Potion: Restores 30% of an ally's health.
  • Ether: Restores 30% of an ally's stamina.
  • Hiroji's Disrupt skill:
    Damages an enemy. Reduces DEF, WILL by 25% (1-3 turns). [Uses]/8 to evolve.
• The Other series: The Other: Airi's Adventure and The Other: Rosie's Road of Love: Some items, such as:
  • The Other: Airi's Adventure: Life Potion: Recover one unconscious ally + 50% HP.
  • Creme Brulee: Recover one unconscious ally + 20% HP.
• Parameters: The Bragging Rights Reward of the one-time square that allows you to double your attack power is unlocked... after you beat the Final Boss. It's pretty much only useful for the only enemy left (which is a superboss), and that's about it.
• Pokémon:
  • Pokémon Red and Blue: The move, Softboiled, can be used out of battle to transfer 20% of the user's Max HP to another Pokemon.
  • Starting from Pokémon Gold and Silver, "Pokerus" that doubles EV gain, infects multiple Pokemon, and goes away at midnight.
• Prayer of the Faithless:
  • The Unbroken condition confers a 10% reduction in stats and receive less Experience Points from battles.
  • First Aid Kits heal 50% HP.
  • Aeyr's Applied Knowledge passive increases the effectiveness of all healing items by 10%.
• Remnants of Isolation: In the Deluxe version, Healing Liquids are described as:
  Recovers 40% HP to a single character.
• Shantae: Half-Genie Hero: The Bikini Armor prevents half of all damage, a.k.a reduces the damage Shantae takes, by 50%.
• Shin Megami Tensei: Multiple:
  • From the very first game, Life Stones recover 30% of the user's total health.
  • In most games, physical skills require a percentage of HP as their cost. This can be a double-edged sword; on the one hand, the more your health increases the more the cost increases. On the other hand, you can use extremely powerful skills right from the beginning of the game (on New Game Plus).
• The Tales Series, such as Tales of Symphonia, has all healing items heal based on percentage of the target's max HP/TP:
  • Apple Gels heal 30% of the target's max HP.
  • Orange Gels heal 30% of the target's max TP.
  • Melange Gels heal 30% of the target's max HP and TP.
  • Lemon Gels heal 60% of the target's max HP.
  • Pineapple Gels heal 60% of the target's max TP.
  • Miracle Gels heal 60% of the target's max HP and TP.
• Weird and Unfortunate Things Are Happening: The health recovery consumables, but they also have a fixed component as well:
  • Health Drink: "Heals 15% of health +30."
  • Med-Kit: "Heals 30% of health +60."
  • Stellar Vial: "Heals 25% of health +50 to your entire party."

Western RPG

• Divinity: Original Sin II:
  • Elemental resistance reduces the damage a creature takes from that element by a given percent, which stacks additively from multiple sources. If a creature's resistance is greater than 100%, they're healed by that damage type instead.
  • The "Forced Exchange" skill swaps the target's current Hit Points percentage with the caster's. In addition to its offensive uses, it's one of the few safe ways to heal an ally with Decaying or another Anti-Regeneration, without Healing Hands.
  • Resurrection scrolls and the "Comeback Kid" talent both revive a dead Player Character with 20% of their maximum hit points. The "Morning Person" talent boosts this to 100%.
• The Of Pen and Paper series:
  • Knights of Pen and Paper: One of the room items is a rug that gives you 30% more EXP at the cost of losing control of your characters, this works as well as it sounds since anything more then a single Elite Mook will cause your characters to attack at random enemies, while they will all focus your tank when you're unable to heal besides regen.
  • Knights of Pen and Paper 2: Some of the Sport Games room items have this effect:
    • Bowling Set: Receive 5% more XP.
    • Minigold Course: Battles won within the first round grant you 10% extra XP and gold.
• Transistor: All There in the Script, is that the Breach() passive's +20% boost to Turn() Planning Cost is actually just a +20, since that's the only effect that changes Red's maximum amount of that stat, and only one copy of every passive can be used, so being a fixed increase instead of a percentage multiplier is functionally the same in this case.

First-Person Shooter

• The Borderlands series: Over multiple games:
  • Borderlands 2: features the Random Drop Booster, "Vault Hunter Relic" (a Pre-Order Bonus or Paid DLC) that gives a +5% chance of rare loot drops. Specifically, it makes White-tier loot more likely to become Green-tier loot.
  • Borderlands: The Pre-Sequel!: Damage Over Time from being in a vacuum without oxygen is a percentage of maximum Hit Points per some time-step.

Massively Multiplayer Online Roleplaying Game

• Elsword: the damage of both normal attacks and offensive skills tend to use a percentage (often more than 100%) of the value of either Physical Attack stat or Magical Attack stat depending on the kind of attack used.

Simulation Game

• Black & White 2: Several buildings have a percent-based bonus on the quantity of food, wood, or ore gathered by workers, which diminishes with the building's distance from the resource and the storehouse. Some, like the University, have a percent-based bonus on those bonuses.
• Pharaoh: Tax rates can only be set as a percentage of income.

Puzzle Games

• Gems of War: Spells' numerical effects are sometimes based on a percentage of certain stats, rounded down. For example, the Widow Queen's spell does damage of [(Magic / 2) + (Sacrificed Troop's Life / 3) + 1].

Roguelike

• Fairyside: Damage Multiplier increases by 0.5 can be bought in shops to take it from the starting x1 all the way [[Cap to x4]].

Third-Person Shooter

• In Warframe, mods apply a percentage increase (or decrease) in the stat they modify. For instance, the Serration mod provides a 200% increase to a rifle's damage at max rank. These effects can stack additively or multiplicatively depending on the type of mod. The effects of mods that affect a Warframe's Ability Strength, Ability Duration, Ability Deficiency, and Ability Range are displayed as percentage values in the Arsenal.

Non-Video Game Examples:

Literature

• Princesses of the Pizza Parlor: In Princesses in the Darkest Depths, when talking about how many cookies has been made, the Batchwork feat and its Tiered by Name enhanced versions or replacements, first triples, then doubles production, along with a magical artifact:
  Uncle: Well, normally it's one per hour, but I've got this feat, Batchwork, which ups that to three... [...] Plus Improved Batchwork, and Greater Improved Batchwork, to six and then twelve. [...] That item halves the cooking time, or doubles production. Six the one and half-dozen the other.
• Vainqueur The Dragon: As said in the first chapter, the Noble class's Old Money skill, which is a Random Drop Booster:
  double the chances of monsters dropping treasure after death.

Tabletop Games

• Dungeons & Dragons: Multiple:
  • Early editions of Advanced D&D:
    • The Ray of Enfeeblement spell reduces the target's Strength by 25% plus 2% per caster level over three. It is not explained in the spell description what happens if a creature loses a percentage of one point of strength (presumably it would be rounded up or down as appropriate).
    • When someone wears a vampiric Ring of Regeneration and harms an opponent in hand-to-hand combat, the ring restores Hit Points of damage taken by the wearer equal to half (50%) of the damage they inflict on the opponent.
    • A Ring of Spell Turning can reflect a percentage of any spell used against the wearer. The greater the percentage reflected, the better the wearer's saving throw against the spell.
    • Deities & Demigods Cyclopedia:
    • "Arthurian Heroes" section. King Arthur's sword Excalibur has a scabbard that causes all thrusting and slashing attacks against Arthur to do only 50% of normal damage.
    • The Celtic deity Manannan Mac Lir has a trident that causes damage equal to 25% of the target's maximum Hit Points by touch. The magic item known as the Tathlum does damage equal to 25% of the target's maximum Hit Points normally and 50% if the target is a relative of the person whose head was used to create the Tathlum.
    • Classical Mythology. The touch of the goddess Tyche does damage equal to 50% of the target's maximum Hit Points.
    • Japanese mythology. The deity Daikoku has a mallet that shrinks the target it hits to 50% of its normal size. Anyone attacking the deity Ebisu hits only 50% as often as they should and does only 50% of normal damage when they do hit.
    • Melnibonean mythos. The magical sword Stormbringer drains 50% of the target's Character Levels if the target makes its saving throw.
    • Sumerian mythos. If the deity Ki gives the "luck of the gods" to someone, that person will only take 50% of normal damage from attacks. If Ki is forced into combat herself, she also only takes 50% of normal damage from attacks.
  • 4^th Edition introduces a "Healing Surge" mechanic, which can be cashed in under specific circumstances for a character to heal a base value of 25% of their maximum Hit Points.
  • Starting in 4^th Edition, a full night's rest goes from healing a set amount of Hit Points to completely replenishing the character's HP.
  • 5^th Edition:
    • Creatures take half the usual Hit Point damage from a damage type they have Resistance against. Third and Fourth editions use a fixed amount of Damage Reduction instead, while editions older than that use variable percentage resistances (so you could find a magic item that gave you 15% resistance to fire damage, while a monster might have 75% resistance to lightning damage).
    • The "Ray of Enfeeblement" spell causes the target to deal half the usual damage with Strength-based weapon attacks.

---